Ethel Browne, Hans Spemann, and the Discovery of the Organizer Phenomenon

9 Pages·1991·3.2 MB·English

by  H M Lenhoff

Reference: Binl Bull 181: 72-80. (August,
Ethel Browne, Hans Spemann, and the Discovery
of the Organizer Phenomenon
HOWARD M. LENHOFF
Department ofDevelopmentalandCellBiology, UniversityofCalifornia, Irvine, California 92717
Abstract. Ethel Browne Harvey(1885-1965) will be fa- to deliver a prestigious Friday Evening Lecture at the
miliar to some as a researcher on the embryology ofsea MBL, in 1944. Her husband was the Princeton physiol-
urchins. Few, however, know her as Ethel Browne who, ogist, E. Newton Harvey, known for his pioneering work
as a graduate student, published, in 1909. a remarkable on bioluminescence.
paper demonstrating for the first time the induction by a Ethel Browne received hergraduatetrainingatColum-
transplant ofasecondary axisofpolarity in thehost. This bia University (1906-1913). While there, she was very
processwaslaternamed "organization" bySpemann and productive, having published six papers, and was greatly
Mangold (1924) in a paper that led to Spemann's being influenced by T. H. Morgan and E. B. Wilson. Her dis-
awardedtheNobel Prize. Whydid the Nobel Committee, sertation, underWilson'sguidance,wasacytologicalstudy
or other embryologists for that matter, not connect of the male gametes ofthe aquatic hemipteran, Nocto-
Browne's discovery with that ofSpemann and Mangold? necta. She participated in and initiated a numberofother
Did they consider the development ofhydra as being too studies, and was a junior author on a short note about
remote from that occurring in embryos of vertebrates'? selective fertilization with T. H. Morgan (Morgan et al.,
Didthe 1909 paperofEthel Browne in anyway influence 1910).
the thinking of Spemann or Mangold, although it was Students ofthe biology ofhydra, however, will think
never referred to in any ofSpemann's papers? In light of ofEthel Browne as the first person to demonstrate that a
newinformationaboutSpemann'sknowledgeofBrowne's transplant could induce a secondary axis ofpolarity in a
work, we also can ask a number ofquestions about the host(Browne, 1909). A similarprocess in amphibian em-
interplay of basic prejudices in the reception accorded bryos was later named "organization" by Spemann and
Browne's work. Mangold (1924). Thestoryofthatworkby Ethel Browne,
and some unanswered questions about how her findings
Introduction were received, are the subject ofthis paper.
Theexperimentsreported in herremarkable 1909paper
Ethel Browne Harvey (1885-1965) (Fig. 1) is perhaps were carried out during "thewinters of 1906-1908," and
best known to biologists for her research on sea urchin in the first paragraph ofthatpapersheacknowledgesT. H.
eggs,andespecially forheruseofthecentrifugetoseparate Morgan for his "kind interest and help." She then de-
the egg into nucleated and enucleated parts. These and scribes a series ofcarefully planned and executed exper-
many ofher other contributions are summarized in her iments on hydra. These experiments appear homologous
classic volume. TheAmerican ArbaciaandOtherSea Ur- tothe Nobel PrizeexperimentsofSpemannand Mangold
chins(\956). (1924), ifweconsiderthe mouth tissue ofthediploblastic
Long-time associates of the Marine Biological Labo- hydra to be developmentally like that of the lip of the
ratory (MBL) at Woods Hole, Massachusetts, may re- blastopore ofthe amphibian embryo. Why did the Nobel
member her as a summer researcher on sea urchins, as a Committee not recognize her discovery? Did it consider
trustee ofthe Laboratory, and as only the third woman the hydra's development too remote from that occurring
in embryosofvertebrates? Although itwasneverreferred
Received 9 October 1990;accepted 30April 1991. to in any of Spemann's papers, did the 1909 paper of
72
BROWNE. SPEMANN, AND THE ORGANIZER PHENOMENON 73
Finally, this case study raises questions about the pos-
sible interplay of basic prejudices: (1) those of medical
scientists in general, and the Nobel Committee in partic-
ular, in using anthropocentric criteria when evaluating
research in the biological sciences; and (2) those ofmale
scientists in evaluating the research of female scientists,
especially the work offemale graduate students or offe-
males who have no significant academic rank.
The Nobel Prize Experiment ofSpemann and Mangold
Mangold's experiment involved taking a piece ofthe
lipoftheblastoporeofthegastrulastageoftheamphibian
embryo and grafting it to the wall (flank) ofanother gas-
trula at a site distant from the host blastopore (Fig. 2). In
somecases, sheactuallygraftedtheliptissue,andinother
casessimplyslippedtheliptissueintothehost'sblastocoel.
Further, to prove that the transplanted tissue actually in-
duced changes in those of the host. Mangold took the
transplant from a pigmented embryo ofone species and
grafted it to an unpigmented embryo ofanother species.
Theresults, ofcourse,wereremarkableandunexpected.
The small piece ofgrafted tissue "organized" the tissue
' nexttoitin thehost, "inducing" ittodevelopasecondary
axis ofpolarity so that the original tissue ofthe host de-
veloped into two embryos rather than one (Fig. 2).
This discovery rocked the world ofembryology. Hilde
Mangold, inthelaboratoryofHansSpemann, had shown
that a piece ofembryonic tissue was capable ofinducing
adjacenttissuetodevelopinaspecific manner. From that
Figure 1. Ethel Browne Harvey (1885-1965). Taken in 1928; from moment, thesearch forthe nature of"theorganizer" was
theArchivesoftheLibrary,MarineBiologicalLaboratory,WoodsHole, on. and for years biologists would carry out a variety of
Massachusetts. imaginativeexperiments, hopingtoidentifytheorganizing
principle (see Hamburger. 1988). None succeeded until
recently. It now appears that Melton and his associates
EmtahnelnBorroMwannegoilnda?nyThweasye ainnfdlureelnacteedthqeuetshtiinoknisngaroefqSupiet-e (teh.agt.,pespeetiRdeuigzroiwAtlhtfaabcatoarnsdaffMeecltthoon,me1o9b8o9x) gheanvees.sThhoewinr
provocative inlightofnewinformation about Spemann's findings may provide a key to understanding the elusive
knowledge ofBrowne's work.
I will first discuss the similarities between the Nobel "orWghaanti,zert"heinn,fwroegrse. the experiments of Ethel Browne
Prize experiments of Spemann and Mangold (1924) in 1909), and how similar were they to those ofSpemann
which the process ofembryonic induction (i.e. the orga- a( nd Mangold (1924)?
nizerphenomenon)wasdemonstrated, andthe 1909work
of Ethel Browne, in which she showed that a piece of Key Discovery ofEthel Browne on Induction in Hydra
hydra mouth tissuegrafted toanotherhydrawould induce
the formation ofa secondary axis ofpolarity in the recip- Ethel Browne (1909) described how the hypostomal
ient. tissue (i.e.. the tissue making up the mouth area ofa hy-
Second, I will consider newly discovered evidence dra), when grafted at a certain site in the body wall of
showingthat Spemann was aware ofBrowne's work long another hydra, gave "the necessary stimulus to call forth
before Hilde Mangold(nee Proescholdt)began herfamous the development ofa new hydranth" at that site (Fig. 3).
organizer experiments. In addition, there is the provoc- Although she did not use the word "organizer" in re-
ative information that Mangold had worked on hydra porting her findings, herexperiments describe, forthe first
immediately before initiating her work on amphibian time, the induction or"organization" ofasecondaryaxis
embryos. ofpolarity. Furthermore, ifwe consider the diploblastic.
74 H. M. LENHOFF
Primary
Axis
Primary Embryo
Induced
Secondary
Embryo
Induced
Secondary Axis
Figure 2. Mangold-Spemann transplantation experiment. Mangold removed thedorsal lipoftheblas-
topore from a donor amphibian embryo (stippled), grafted it to the flank ofa host embryo, and thereby
induceda secondary axisofpolarity in the host that eventuallydeveloped intoasecondary embryo.
sac-like hydra as a diploblastic gastrula with a ringlet of derm and endoderm separated by a thin basal mem-
tentacles emanating from the lips surrounding the "blas- brane called the mesoglea (Fig. 4). At one end ofthe an-
topore," her results bear a remarkable resemblance to imal is the "hydranth," the part involved in feeding (the
those of the organizer experiments that Spemann and captureand ingestion ofprey). Between the ringletoften-
Mangold ( 1924) reported 15 years later using amphibian tacleson the hydranth isthe mouth, an opening made up
embryos. oftissue called the hypostome (Fig. 4).
The hydra can reproduceasexually, by producingabud
Structure and Development ofthe Diploblastic Hydras at about the middle ofits tubular body (Fig. 5A). Once
Before reviewing Browne's key experiments in detail,
it is important to understand the basic structure and de-
velopment ofhydras. The hydra is a simple diploblastic Tentacles
epithelial animal made up of two cell layers the ecto-
- Hydranth
Hypostome
- Mesoglea
Digestive Cavity
Figure 3. Browne transplantation experiment with hydra. Browne ; .pi-Endoderm
removedapieceofthehypostome(see Fig. 4)with asingletentacle(as
a label) from adonorhydra, grafted ittotheflank ofahost hydra(#1), Ectoderm
and thereby inducedasecondary axisofpolarity in thehost(#2)which
eventuallydeveloped intoasecondaryhydranth(seeFig. 4). Thefigures
arethoseofBrowne(1909). Figure4. Diagram ofahydra illustratingitsmajorstructures.
BROWNE, SPEMANN, AND THE ORGANIZER PHENOMENON 75
A. Budding
About 2 - 3 days
B. Separation of Secondary Axis
About 3 - 6 weeks
Figure 5. Difference between budding(A) and separation ofa secondary axis ofpolarity (B) in hydra.
Thesecondaryaxisofpolaritycanbeestablishedbytheinduction methodofBrownedescribedinthetext,
or by a kind oflongitudinal fission, which can occur naturally orbe initiated by cutting the upper halfa
hydrapartwaydown the middleofthebodycolumn.
this bud starts to form, it will normally develop a basal serve as a marker, and grafted that tissue to various sites
discatthepointofjunction betweenthebudand parental alongthe body wall ofanother hydra ofthe same species.
body tube and will detach from the parental body tube She found that only when the hypostomal tissue (with
as a small, fully developed hydra within 2-3 days. the tentacle) was grafted to about the center ofthe body
Some species of hydra are diecious; others are mone- tube, a "new hydranth regenerated there." That new hy-
cious. Thegonadsare usually notpresentwhentheanimal dranth initially had one long tentacle, the one from the
is reproducing asexually by budding, and they appear at grafted tissue (Fig. 3).
different times in different species. The zygote then de- Within a few days, this second hydranth developed a
velops into a miniature diploblastic hydra that is struc- mouth and tentacles and became a secondary axis ofpo-
turally homologousto adiploblasticgastrulaofa number larity to the body ofthe host hydra. This new hydranth,
ofinvertebrates (Fig. 6; Brien, 1965). Note, however, that with its accompanying body, was not a bud. Recall that
the embryo ofhydra does not develop by the classically a new bud develops a basal disc ("foot") and detaches
described process of the invagination of a blastula, but from the parent stalk within 2-3 days after developing
ratherbya processsimilartoadelamination ofcell layers (Fig. 5A). The secondary hydranth induced in Ethel
(Brien, 1965). Browne's experiment, to the contrary, remained on the
parental bodytubeforweeksbeforeiteventuallyseparated
Ethel Browne's Basic Experiments by a sort oflongitudinal fission (e.g., Fig. 5B). Browne's
In her first induction experiments, Browne removed a experiment is simpleto perform; I have repeated it several
piece ofthe hypostome with a tentacle attached to it to times with very little difficulty.
76 H. M. LENHOFF
Figure 3 showsclearlythatanewhydranth wasinduced
and that it developed a secondary axis of polarity by
drawing out with it some more parental tissue. Browne
asked the key question as to whether the transplanted
tissue actually induced the formation ofa new hydranth,
or whether the cells ofthe transplanted tissue multiplied
and then, themselves, formed the new hydranth.
To test these two possibilities, Browne devised an ele-
gant but simple experiment involving pigmented and
nonpigmented tissues. As a transplant, she used tissue
taken from a green hydra the intracellular algae ofwhich
had been removed byaprocessdescribed twoyearsearlier
by Whitney (1907). Normally theendodermal cellsofthe
green Hvdra viridissima are laden with symbiotic green
algae. The host tissue in Browne's experiment was such
a green hydra ofthe same species. Through this experi-
ment involvingthe use ofa piece ofnonpigmented tissue
transplanted to a pigmented host of the same species,
Browne showed conclusively that the pigmented host tis-
sue wasorganized by the nonpigmented transplant tode-
velop into a hydranth and a secondary axis of polarity
Figure 7. Result ofBrowne's experiment in which she grafted, as
(Fig. 7). donor, a piece ofthe hypostome and a tentacle taken from a "green"
Browne did numerous otherexperiments proving that hydrawhosealgaehadbeen removed, totheflankofagreenhydrathat
it was only the hypostomal tissue (analogous to the lip of still contained its endosymbiotic algae. The transplant induced a pig-
the blastopore of a gastrula) that would induce the for- mentedsecondaryaxisofpolarityinthehost.ThefigureisthatofBrowne.
mation of both a hydranth and a secondary axis of po- 1909.
larity. As she said, "it depends . . . entirely on the dif-
ferentiation ofthe grafted material." That is to say, only
the hypostomal tissue had this organizing capacity, not
other tissues ofhydra, such as a tentacle. Since the pub-
lication ofBrowne's paper (1909), a number ofother in-
vestigators have used her findings in their experiments
describing the developmental capacities ofhydra tissues
(e.g.. Yao. 1945; Webster and Wolpert, 1966).
Was Either Spemann or Mangold Aware of Browne's
Experiments Before Beginning Theirs?
Thecloseanalogiesbetween theexperimentsofBrowne
(1909) and the Nobel Prize experiments ofSpemann and
Mangold (1924) are manifest. Both papers showed that
tissue taken from specific regions ofan organism or em-
bryo,whentransplanted,couldorganizetheadjoininghost
tissue and induce it to form a secondary axis ofpolarity
that is similar, in most respects, to the primary axis of
polarity. But more importantly, through the use ofpig-
mented and nonpigmented tissues, both sets of experi-
ments proved conclusively that a true organization oc-
curred, and not agrowth and reorganization ofthe trans-
planted tissues. Browne's experiment was even more
Figure6. A younghydrajustasitemerged from theembryo(Bnen. conclusive because she used pigmented and nonpig-
1965). mented tissues from organisms of the same species.
BROWNE. SPEMANN, AND THE ORGANIZER PHENOMENON 77
*^
/? -i
THE PRODUCTION OF NEW HYDRANTHS IN
HYDRA BY THE INSERTION OF SMALL'*6&&***+~.
GRAFTS
ETMBL N. BBOWTJI
THE JOURNAL OF EXPERIMENTAL ZOOLOGY
Volume vn No.
i
AUGUST.
1909
Figure8. Coverpageofreprint ofBrowne's 1909 paperfound in Spemann's reprintcollection.
whereasSpemann and Mangold (1924)usedtissuestaken breadth, and, as Viktor Hamburger (1988) has noted,
from two different species. Spemann was aware ofTrembley's famous inversion ex-
Recently, in a roundabout way, I received conclusive periment and wanted to see if, aftera hydrawasinverted,
evidencethatHansSpemann wasawareofBrowne'spaper its ectoderm would be converted to endoderm, and vice
as early as a few months after its publication. The infor- versa. Spemann apparently had notroublein considering
mation came to my attention as a result of a paper on hydra's two cell layers as analogous to the ectoderm and
Abraham Trembley published in Scientific American endoderm of embryos. It was only after Mangold's at-
(Lenhoffand Lenhoff, 1988). In response to that paper, temptstoinverthydrafailedthat,accordingto Hamburger
wereceived kind lettersfrom a numberofscholars,among (1988), Spemann suggested that she transplant thedorsal
them Professor K. Sanderofthe Albert-Ludwigs-Univer- lip ofone newt gastrula to the flank ofanother newt gas-
sita't in Freiberg. Professor Sander is the current Director trula.
ofthe University's Institute for Biology (Zoology), once Responding to Sander's letter, I asked ifhe could find
directed by Spemann. In his letter (30 May 1988), Pro- any evidence that Spemann had been aware ofBrowne's
fessor Sanderstated that, at Spemann's suggestion, Hilde experimentson hydra(i.e.. thosepublished in 1909). Pro-
Mangold's original thesis topic was to repeat Trembley's fessor Sander replied (1 1 July 1988) with two pages of
experiment of turning hydra inside out, then following photocopied material. The first shows the cover page of
the fate of the ectoderm and endoderm in the inverted Browne's reprint found in Spemann's collection (Fig. 8).
animals. Spemann, we know, was a biologist of great Note that the paper by Browne had a published date of
78 H. M. LENHOFF
August 1909 and that Spemann. under his signed name, lens induction (1901). If we accept that interpretation,
wrote the date "October, '09." In the upper right corner thenwealsowould havetoacceptthatSpemann had read
is Ethel Browne'ssignature afterthecourteous, sometimes her paper and must have believed that Browne had truly
routine, "Compliments of." Thuswe know thata reprint observed a case ofinduction, albeit a remarkable one in
ofEthel Browne'spaperwasin Spemann'spossessionsoon which a secondary axis ofpolarity was induced.
afterherpaperwas published, andthatitwasinhisreprint Fromtheevidenceonhand, however,wecanonlycon-
collection. clude that: (1) Spemann wasa man ofsome breadth who
From this single piece ofevidence, we cannot say con- was familiar with the zoological, as well as the embryo-
clusivelythat Spemann readthe paperfirst in thejournal, logical literature; (2) he possessed a signed reprint of
wasinterested in it, and wrote (orhad someone write) for Browne'spaperand received itsoonafteritwaspublished;
a reprint. Although I find it hard to believe that, in 1909, (3) someone underlined the only phrase in the paperthat
a graduate student, on her own, would send her reprint contained the word "induced"; (4) Spemann considered
unsolicited to a distinguished professor, that may have the freshwater hydra a suitable experimental system for
been the case. Perhaps because her paper dealt with the thestudyofdevelopment;and(5)at hissuggestion, Hilde
induction phenomenon, Browne mayhavesentthepaper Proescholdt (Mangold) had been working on hydra im-
to Spemann unsolicited because he had published in that mediately before she began her research on the newt. All
field earlier (Spemann, 1901). Or, because T. H. Morgan else remains speculation.
was acquainted with many European embryologists, she
may have sent the paper to Spemann at Morgan's sug- Was Spemann Influenced in any way
gestion. Another scenario would be more typical: Spe- by Browne's Findings?
mann saw the paper, read it (or parts ofit), and wrote to
Browne for a reprint. Wecannotbesure. Forthesakeofargument, however,
The other photocopied item sent to me by Professor let us assume that Spemann was influenced by Browne's
Sanderistheonlypageofthearticlehavingany markings work, and that he saw the direct link between Browne's
(Fig. 9). Only one phrase is underlined one containing findings and his own. Ifsuch was the case, was Spemann
theword "induced" and it isaccompanied by an excla- the sort ofperson who would acknowledge such a debt?
mation mark in the margin. This is the only place in Horder and Weindling (1985, p. 204), in their article
Browne'sentirepaperwhereshe usedtheword"induced;" titled "Hans Spemann and the Organiser," attempt to
elsewhere she used such expressions as "stimulated to analyze the complex nature ofthe man as a scientist and
form." (Interestingly, she used the word "induced" re- asan individual whohad "astrongsenseofnationalism."
garding a case in which induction did not, and, as she Theywrite, "Spemann confessed in momentsofhumility
proved, could not occur.) Nonetheless, even the presence that hewasoften proneto forget relevant literaturewhich
of this underlining is not absolute proof that Spemann hadearlierimpressed him. . . ." From mylimited search
got some ideas from Browne, for we have no way of ofthe literature, I can find no reference to Ethel Browne
knowing with certainty whether it was Spemann himself in any ofSpemann's publications (e.g., Spemann, 1938).
who entered the underlining, nor when the underlining We can get a little more insight into Spemann's per-
wasdone. Butwould agraduate student, postdoctoral fel- sonality from an interesting anecdote revealed by Viktor
low, or a visiting scholar have marked the Professor's re- Hamburger in hisbook on TheHeritageofExperimental
print? More likely Spemann himselfunderlined theword Embryology: Hans Spemann and the Organizer (1988).
"induced," for he had been working on lens induction Hamburger notesthat Spemann did not put his nameon
since the turn ofthe century (Spemann, 1901). papersoriginatingfrom thethesisresearch ofhisgraduate
Asarelatedinterpretation, onecritic hassuggested that students, at least he did not in the cases of Hamburger
Spemann may have underlined the phrase "induced to and Holtfreter. With Mangold, however, Spemann not
form" and entered theexclamation mark because hewas only put his name on the publication that reported the
peeved that Browne did not refer to his earlier work on resultsofherthesisresearch, but, despite herprotests(ac-
The insertion ofa tentacleintothe circletoftentaclesofa normal
hydra in no instance induced the formation of a new hydranth.
The tentacle either remained as grafted or instigated theoutgrowth
Figure 9. Only excerpt showing underlining in reprint ofBrowne's 1909 paper found in Spemann's
reprintcollection.
BROWNE. SPEMANN, AND THE ORGANIZER PHENOMENON 79
cording to Hamburger), he even insisted on putting his Great Britain. In both instances the paper polarized the
name first. Some think he did the correct thing; Ham- audiences, even though most agreed thattheexperiments
burger (1988) writes that "Spemann was perfectly right ofEthel Browne, likethoseofHilde Proescholdt Mangold,
in claimingprecedence . . . [because] sheapparentlydid demonstrated the phenomenon ofinduction ofa second-
not fully realize the significance of her results." I could ary axis of polarity. Some felt that Ethel Browne's dis-
argue, however, that Mangold, who had been workingon covery was neglected, either because she was a woman
hydra just a few years earlier (Hamburger, 1988), was graduate student, or because it was not made on a ver-
aware ofthe literature on hydra including Browne's 1909 tebrate embryo.
paper, recognized thesignificance ofBrowne'sexperiment Opposingargumentswentasfollows. (1) Herworkwas
using pigmented and nonpigmented tissues, and, inde- ground-breaking, but she really did not understand the
pendently ofSpemann, decided to conduct a similar ex- significanceofherfindings. (2) Ifshedid not usetheword
periment usingheramphibian embryos. Mangold died in "organizer," then she did not discover the phenomenon.
an explosion ofa gasoline heater in her kitchen in 1924, (3) She was a graduate student and did what a graduate
the same year that her classic paper was published. She student issupposedtodo: theworksuggestedby hermen-
neverlivedtolearn that herthesiswork had ledtoa Nobel tor. (4) "I knew her for years at Woods Hole, and not
Prize. once did she ever mention to me her experiments on
hydra."
The Nobel Prize From reading Browne's paper closely, it seems abun-
Mangold did not share the Nobel Prize with Spemann dantly clear that she understood the significance of her
because the Prize is never awarded posthumously. But findings. In fact, ifwe accept the possibility that she sent
shouldnotEthel Brownehavesharedintheprize?I believe her paper to Spemann unsolicited, then this would be
so; her results were essentially the same as those ofSpe- evidence that she did understand that her findings dealt
mann and Mangold, and her published work preceded with induction. When I presented this paper in South-
tkhneoirwsnbyab1o5utyeaErtsh.elHoBrwowcnoeu'lsd wthoerNkoibfeSlpCeommamninttneeevehrarvee- asemaprtcohne.r oEnnghlyadnrdo,idsDra.t StheearMsBCLr,owemlald,eaalcoonmg-mteinmet rree--
ferred to it? The usual way by reading the literature, or garding Ethel Browne Harvey that he subsequently re-
by having as advisors scholars who knew the literature. peated in a letter dated 3 August 1989:
But iftheyhadreadherpaper,wouldtheyhaverecognized Wehappenedtomeetasshewasleavingthe MBL [Marine
its significance? Probably not; most biologists ofthe time Biological Laboratory] building where she had a lab.
(andthereafter) failedtorecognizethesignificanceofEthel Somewhatoutoftheblueshesaid: "You knowthatitwas
Browne's extraordinary findings. 1 who first discovered the organizer." Not an exact quo-
Are there other reasons why Ethel Browne's discovery tation. I replied that I did recognize that this was indeed
was little heralded? Did the members ofthe Nobel Com- the case. . . .
mittee selecting the awardee for the prize in physiology Ethel Browne Harvey died 2 September 1965. There is
and medicine at that time recognize primarily those dis-
coveries that had obviousconnections with human health an obituary in The Biological Bulletin (Vol. 133: 11). It
and development? As such, was research that had some does not mention her transplants with hydra.3
conspicuousanthropocentric connection more often rec-
ognized? Did this oversight reflect the regressive aspects Acknowledgments
ofoverspecialization, in that a developmental finding in
an organism past theembryonic state was notconsidered I thank Dr. Richard Campbell for pointing out the pa-
important to embryology? (Only in recent times have we perby Paul Brientome. Dr. KlausSanderforuncovering
seen graduate programs and books categorized as "de- the reprint of Ethel Browne's paper in the collection of
velopmental biology," ratherthan asembryology alone.) the late Hans Spemann, and Dr. Sears Crowell for his
Was Ethel Browne's work ignored because she was a letter recalling his conversation with Ethel Browne
woman with no significant station in academe? Harvey. For editorial comments, I thank my colleagues
I have presented this story to one national meeting1 in at the Developmental Biology Centerat the University of
the United States and to one international congress2 in California, Irvine, and especially my wife and colleague,
1 HistoricalSessionoftheAmerican SocietyofZoologists. San Fran- 3CrowellnotedthatthelastyearthatEthelBrowneHarveywaslisted
cisco.California, December 1988. as an investigator at the Marine Biological Laboratory was 1962. He
: Historical Sessionofthe Fifth InternationalCongressofCoelenterate guessedthatthedateofhisconversationwithherwasinthe"latesummer
Biology. Southampton, England, July 1989. of 1961 or 1962."
80 H. M. LENHOFF
SylviaG. Lenhoffwho, like Ethel Browne, wasagraduate Morgan, T. H., F. Payne, and E. N. Browne. 1910. A method totest
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