Page 1 ISSN00381578 Vol.32 No.1 20March1984. CONTENTS Akira H江rada and Takaaki

114 Pages·2012·17.49 MB·Indonesian

ISSN 0038 1578
Vol. 32 No. 1 20 March 1984.
CONTENTS
Akira H江radaand Takaaki Yamagishi: N1itosis in Stirogyra (Chloro
phyceae) 1
Akira Harada and Takaaki Yamagishi: N1eiosisi n Stirogy戸a(Chloropllycea巴) 10
Shigeru Kumano and i\f. Ratnasabapathy: Studies on freshwater red algae
of Nblaysia IV. Balrロc!wster川llll/.ba!wrellse，s p. nov.f rom SungaiB akar，
Kelantan.明lest N1alaysia 19
Shigeru Kumano: Studies on fresllwater red algae of N1alaysia V. Early
clevelopment of carposporophytes of Brlrachostermlllll cy!indrocelllllare
KUi\1八1'0 ancl 13. lorluoSlIlIl I<l'\iI!\N円 2'1
Kazuyuki Miyaji: 1'h巴 lifehistory stucly on日 sporopllyticform of Stongo・
mort ha-Acrosithollia complex (Acrosiphoniales， Chloropllyta)， CodiolulII
telrocei'idis 1くじCI<L~O; from Notllern japan ・ ・ ・・・・.• (in japanese) 29
Toshinobu Terawaki，K oji N07.awa and Iwao Shinmura: Stllclies on morpllo・
genesis in the early stages of Sargasslllll (Pllaeopllyceae，P lIcales). VI
SargaSSll111 aS)'1/I1nelricu1I1 ................・0・0・0・0・・a・I ー・ (injapanese) 32
Shogo Arai and Akemi Arai: Effects of grazing on algals llccession 1 (in japanese) 43
Teru Ioriya，M asayuki Watanabe and Masaru Haga: Algae in the mOllntain
streams of the Satsunai-gawa River l. Distribution ancl stancling crop .(i n japanese) 52
Masayuki Watanabe，M asaru Haga and Teru Ioriya: Algae in the mountain
streamso f the Satsunai-gawa River2 . Notcso n blue-green algae ........(i n japanese) 60
Masaru Haga，T eru Ioriya and Masayuki Watanabe: Algae int lle mounta川
streams of t11巴 Satsunai-gawaRiver 3. Noteso n cllrysomon日1cs .. . . . (i n Japanese) 65
.・.-
Review
Tomitaro Masaki: Crustose coralline口Igae (in japanese) 71
.・.
Book review 86
Proceedingso f the 8th AnnualM eetings of thc JllJ)uneSe Society of Phycology.. . .. . ... . 87
\
THE JAPANESE SOCIETY OF PHYCOLOGY
日 本藻類学会
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The Japanese Society of Phycology
Th巴]apaneseSociety of Phycology，f ounded in 1952，i s open to all who are interested in an)
aspecto f phycology. Either individuals or organizations may become members of the Society. The
japanese Journal of Phycology (SORUl) is published quarterly and distributed to m巴mbersfree of
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Buisiness Center for Academic Societies Japan，4 -16，Y ayoi 2chome，Bunkyoku，Tokyo，1 13 Japan.
・ ・
Manuscript for the Journal should be addressed to the Japanese Soceity of Phycology，c /o
Laboratory o( Phycology，'l 'okyo University o( F時heries，Konan ，1c home，M inato-ku，'l' okyo，1 08J apan.
昭和58，59年度役員 Olficers for 1983-1984
会 長 /1;.本iJiで (必J;(ノ'J()lji'A:"n President: 1くozoIIl'Ai\IO・ru(Tokyo Univ.o f Fisheries)
!f!;f0幹事・今日!(- 1，政徳(~~J;( ;JcP Ci)ぐア Secretary: Toshinori !<Oi\:i\:O (Tokyo Univ.o f Fisheries)
会社市í~'Ji:: ，': j，'以降IYJ人(1/修)('''f:) TI巴asurer: Takaaki1 くυJJAI~A (Senshu University)
評 議 員 Membersof Executive Council:
1大111 干11大(以北I~;j(Jij'UVf究Jリr) Kazuo AI(IYA^IA (Tohoku Reg.l 'ish. Res.L aboratory)
秋111 鋭(，i:，i'1H人'苧 IVlasaruAIくIYAi\IA (Shilllane University)
イI11 削除 UkJ;(JJくJI(}..:"t) Yusho ARl'GA (Tokyo Univ. of Fisheries)
午14{ 光b11:(ffL叫ん'下I\liLsuoCIIIIIAI~λ(UniversLy of Tsukuba)
品 j:I，-':(筑波j、'';':) TerullliLsu lluRI (University o[ Tsukuba)
diH 前IUI:(~U;()、'下 Terunobu lClll\iIURA (University of Tokyo)
'r':' jl: J.1):: (て三五木ρ(":) Toshio lWAI( \Ili巴 Univ巴rsity)
般11，: IJI三 ()，:!>MJ，'f:) く0201日ASA(Osaka University)
IJy淳 一俊(11本人γ・ くazutosiNISIZAWA (Nihon University)
型fiJ( lf'i治(児児仏大'J:)くojiNOZA\ \・A (Kagoshillla University)
'n
奥川武リ)(九州大 Takeo OKUDA (Kyushu University)
阪)!:Ui[，ιüJr~ c/liIIEu}，つ!:) Yoshio SAKAI( llokkaido Uni ve、rsity)
{i: 11 p~~俊( ei} i:)(''!") IVloriloshi TANIGUCIII( Mie Uniersity)
JJ ，W: 潤ー (市IJÿiÍIjl^~ノ1(賄側''ICI町) Junichi TSUKII)ATI:: (NanseiR eg. Fish. Res.L aboratory)
/IIjlll!，j リj(J;( r~[;)、'n Isalllu Ui\IEZAJ(1( 1くyotoUniversity)
111 ~，弘11j!{ C-/U仮i.D:).、学 HiroLoshiYA i\1Ai\IOTO (llokkaido University)
編集委員会 EditorialBoard:
~OJ主 ニサIl II({雌(見υ;(/J(pj~)ぐγAkio IVlIURA ('1、okyoUniv. o[F isheries ，) Editor-iト，chief
，;i.í~ 'Jr 凶行 え (~U;υ'J(Pr，).、''/:) Teru IURIYA (Tokyo Univ. of Fisheries)，S ecretary
委 l1 秋111 催U:，'，I1U，"f:) \Ilasaru AKIYAi\IA (Shimanc UlIiversity)
n イftL tl;JJ1J (J，/U;(7](J来j、γ YlIshoARUGA (1、okyoUniv.o f Fishereies)
H 千品!li(，光u.fーi::(筑波}.，:''t) MitslIo CIIIIIARA (Universily o[ Tsukuba)
H :Ij (筑波j、学 Te，・uIll、ilslIlloRI (UniversiLy orT sukllba)
" kl~(1，: wf二三(大阪)("/:)く0201VASA(Osaka Universiy)
1/:附共U:(f~ (:，[0ぐγ:)n llideo IWAsAJ(1( iVIi巴 Univ e rsity )
!，I，\~、 京尚C-IUiI.i.illJぐ、 MlIn巴nao1くURUGI(Hokkaido University)
u
' 小l本 弘(J，/u;(学工 、'下 lIiroIllll1くOBAYA 51 (Tokyo Gakug巴 University)
'' lE!i'c'，';Ij(郎C-Iヒ海道jぐ下 TOIllitaroMASAKI( Hokkaido University)
'i イi111 i'，{ifi (J壬山.:u.;''t) Seiji MIGITA (Nagasaki University)
'
'' fly(干一俊 (n>1;:)、学くazutosiNISIZAII'A (Nihon Uni吋 rsity)
山川 JよソtC-Iヒ海道k'Y:) Tadao YOSIIIDA (Hokkaido Univer
Jap. j. Phycol. (Sorui) 32: 1-9. March 20，1 984
Mitosis in Spirogyrα(Ch1orophyceae)
Akira HARADA* a nd Takaaki YA MAGISHI**
本SeiyuSenior High School，C hizuka，Y ao・City，Osaka，5 81 Japan.
**Biological Laboratory，C cllege 01 Agriculture and Veterinary Medicine，N ihon
University，K am2Ino，F ujisawa，K anagawa，2 52 Japan.
HARADA，A . and YA NIAGISHI，T . 1984. Mitosis in Spirogyra (Chlorophyceae) jap. J.
Phyco .l32: 1-9.
Mitosis in three species of Spirogyra，S . crassa，S . crassa X and S. hunanensis， was
observed. The chromosome numbers of S. crassa and S. crassa X were 12 and 6r espec-
tively，a nd S. hunanensis had four chromosomes. The chromocenters and nucleoli，t he
origin and formation of the chromosomes，th e nucleolar substance，t he nucleolar organizing
chromosomes， the parallel separation of chromatids， the stickiness of chromosomes and
cytokinesis were observed during the mitotic cycle.
Key /ndex Words: Chlorophyceae; chromocenter; chromosome; cytokinesis; mitosis;
N. O. chrom:Jsome; nucleolar substance; parallel separation 01 chromosome; sticky
chromosom2; Spirogyra.
WISSELINGH (1900) observed mitotic divi- TSUNO and IIYAMA (1971). TATSUNO and
sion in Spirogyra and mentioned that chro- lIyA MA published ar eport on the chromosome
mosomes are derived partly from the nucleolus numbers of some species，i ncluding three
and partly from the karyoplasm. Since then， species having only two chromosomes.
special attention has been paid to the origin However，m any questions on the mitotic
of the chromosomes and differing opinions process in Spirogyra remain，a nd in the pre-
regarding this point have been presented by sent paper，mi tosis in three species，S pirogyra
various workers (DORAISWA MI 1946). crassa Kutz.，S . crassa X and S. hunanensis
GEITLER (1930) and DORAISWA MI (1946) ]ao，is described.
investigated the process of mitotic division
and suggested that the chromosomes are
Materials and Methods
derived solely from the karyoplasm and noted
the existence of the nucleolar substance. Fertile filaments of S. crassa were collected
WISSELINGH (1900)， GEITLER (1930) and from rice fields of Shigisan，N ara Prefecture，
GODWA RD (1950) mentioned the existence of in November， 1968，a nd from ]anuary to
nucleolar organizing chromosomes. GODWA RD November，1 969. S. crassa X was collected
(1954) also observed bipartition of the chro- from Yata，N ara Prefecture，f rom November
mosomes using the iron alum acetocarmine 1971 till May 1972. The taxonomic charac-
method (GODWA RD 1948). GODWA RD (1956)， teristics of this material are similar to that
GODWA RD and NEWNHAM (1965) published of S. crassa， except for the smaller cell
cytotaxonomical studies of Spirogyra. FOWKE dimentions，a nd this material was provision-
and PICKETT・HEAPS(1969，1 969a) reported ally designated as S. crassa X. S. hunanensis
the ultrastructural observations of cell division. was collected from a pond in Fujii，N ara
In ]apan， cytological investigation of Prefecture，i n August，1 971.
Spirogyra was conducted by SUEMAT SU The materials were fixed with acetic-alcohol
(1936)，O URA (1935)， UEDA (1956) and TA - (1 :3) mixture. By mixing the two ftuids
2 !-IARADA，A .a nd YA MlえCfSl-lf，T.
側同."，
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7 8
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Mitosis in Spirogyra (Chlorophyceae) 3
immediately before use，t his fixative gave 1950) were clearly observed (Figs. 2，3 a nd
good results during staining. The fixed 4). When two nucleoli existed in an ucleus，
materials were stored in the same solution， each nuclolus had as ingle organizer track.
and kept in a freezer box. Fixation was Many irregular thread-or rod-shaped chromo-
made at intervals of an hour throughout a centers were seen in the karyoplasm (Fig. 3).
twenty-four hour period， and the most Near the nucleolus，t here was one or two
abundant mitotic material was generally ob- small spherical bodies which were as densely
tained from sunset to midnight. stained as the nucleolus，a nd had been termed
For observation，t he modified WITTMANN'S Nebenkorper by GEITLER (1930) (Fig. 1).
(1965) method was employed，a nd serial treat- However，n o activity of these bodies at any
ments were carried on the slide as follows: time during the division was observed.
1) The fixative was absorbed from the Prophase: At this stage，t he organizer
material by filter paper，a nd the remaining tracks in the nucleolus appeared as compact
alcohol was evaporated by heating. winding cords (Fig. 4). Many chromocenters
2) The material was pretreated with 1N linearly arranged were observed in the
HC1，a nd one drop of 1-4 iron alum 45% karyopiasm. Then，t he chromocenters con・
acetic acid. densed gradually and chromosomes formed
3) Aceto-iron-haematoxylin-chloral hy- (Fig. 4). At mid-prophase，t welve chromo-
drate was added to the materia .l This solu- somes were counted. Two of these were
tion was made by throughly mixing 2.0 gm nucleolar organizing chromosomes (N. O.
of haematoxylin，0 .5 gm of iron alum and chromosome，G ODWA RD 1950) that connected
20 gm of chloral hydrate in 50 ml of 45% with each of nucleolar-organizing region
acetic acid. This mixture used immediately (N.O. region，G ODWARD 1950) in the nucleolus
after melting， and gave clear chromatic and as atellite ahead of the nucleolus (Fig. 5).
results. Furthermore，t he staining ability At late prophase，t he nucleolus changed into
was retained for al ong time. ad eeply stained substance，ca lled the nucleolar
4) Then，t he material was heated，a nd substance (GEITLER 1935)，a nd the two N.O.
squashed with a cover glass. By heating， chromosomes and the ten other chromosomes
the chromosomes were sharply stained and which originated from the chromocenters
the cytoplasm became transparent. located in karyoplasm were compltely en-
veloped in the nucleolar substance.
Metaphase: The nucleolar substance was
Observations.
lenticular in shape and located in the equato-
1) SpirogyrαcrαssαKUTZING (n=12) rial plate of the nucleus as in S. crassa X
Interphase: The nucleus was lenticular， (Fig. 21). Twelve chromosomes in the
and was surrounded by cytoplasm，w hich nucleolar substance were clearly observed at
spread out in all directions as cytoplasmic this stage. Two of these chromosomes were
strands. The nucleus had one，s ometimes the N.O. chromosomes and had as atellite at
two，la rge nucleoli which were seen as bright one end，a bout 12μm in length (Fig. 6).
bodies in living cells (Fig. 1). In these The other ten chromosomes were almost the
nucleoli， two densely stained thread-like same in length，a bout 10μm. By pretreat-
structures，ca lled organizer tracks (GODWA RD ment with 1N HC1，a b anding pattern clearly
Figs. 1-10. Spirogyra crassa (n=12) 1-3. Interphase nucleus: 1. Two nucleoli and Nebenkorper
(arrow) ;2. Organizer tracks in an ucleolus; 3. Chromocenters in karyoplasm; 4-5. Prophase: 4. Two
organizer tracks (arrows) in a nucleolus and bead-shaped chromosomes; 5. N. O. regions (arrows)
pretreated with HCI; 6-7. Metaphase: 6. Two N. O. chromosomes with as atellite (arrow); 7. Sticky
chromosomes; 8-10. Anaphase: 8. Beginning of parallel separation and ladder shaped chromosomes;
9. Symmetric arrangement of chromatids in each daughter nucleolar substance; 10. Two horn-shaped
N. O. chromosomes (arrows). (Scale bars=10 pm).
4 HARf\DA，A .a nd YA~IAGISIII， T
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19 20
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Mitosis in Spirogyra (Chlorophyceae)
5
appeared on the chromosomes of this stage， by the plate.
and the number of bands on each chromosome 2) SpirogyrαcrassαX( n=6)
was nearly constant (Fig. 6). Some of the At the begining of prophase，t he nucleus
chromosomes in metaphase showed some and the nucleolus began to swell up，a nd the
stickiness，a nd were connected with one organizer track in the nucleolus gradually
another by as ticky substance at the end or became loose and short (Fig. 13). At midpro
・
side (Fig. 7).
phase，t he chromocenters connected to each
Anaphase: In early anaphase，t he lenticu- other and formed six bead-shaped chromo-
lar nucleolar substance began to separate somes. Two of these chromosomes were the
parallel to the equatorial plate of the nucleus. N.O. chromosomes (Fig. 14). The nucleolar
Twelve chromatids embedded in this sub- substance was formed as in S. crassa (Fig.
stance were thus moved to the opposite poles. 21). The spindle was organized at four cor-
As ar esult of the separation of the nucleolar ners of the nucleus (Figs. 15 and 16). The
substance into two round shaped disks，a ll barrel-shaped spindle developed gradually and
of the chromosomes began to separate in was finally completed at late prophase (Fig.
paralle .l Then the densely stained portions 17).
of each chromosome began to strech and all In metaphase，t he two N.O. chromosomes
the chromosomes assumed a ladder shape were about 12μm in length and the other
(Fig. 8). As the satellite of the N.O. chro- four were the same shape and about 8μm
mosomes separated later than the other parts， in length (Fig. 18). On the chromosomes，
it was often seen as two trails or horn-Iike banding pattern was clearly observed.
processes between the two nucleolar substance At early anaphase，i n strongly squashed
(Figs. 9a nd 10). The twelve chromatids in preparations，b y bipartition of the chromo-
each nucleolar substance disk was assumed somes，t he densely stained bands stretched，
to have as ymmetric position (Fig. 9). and two parallel chromatids showed al adder
Telophase: The chromatids that reached shape (Fig. 19). At a later stage，t hese
each pole became fragments or rod-shaped chromatids separated from each other，b ut
chromocenters. The daughter nucleolar sub- the satellite of the N.O. chromosomes sepa-
stances changed from ar ound to a spongy rated later，as observed in S. crassa (Fig. 20).
form and then to irregular shaped masses. Finally，a n ew cross wall was formed in the
At the end of telophase，o ne or two nucleoli same way as that in S. crassa.
occured in each daughter nucleus (Figs. 11 3) Spirogyrαhllnαnensis Jao (n=4)
and 12). At the begining of prophase，a bout 20 dot-
Cytokinesis : At late prophase，a ring shaped chromocenters were observed in the
consisting of minute granules appeared inside karyoplasm (Fig. 22). The chromocenters
the cell wall at the middle of the cel .l The gradually joined with each other and formed
ring was identified as two circles of granules four bead-Iike chromosomes. Two of these
which were unstainable and were not affected were connected at their terminals in the
by heating (Figs. 20， 21 and 26). After nucleoli (Fig. 23). In metaphase，f our chro-
nuclear division，t he granular ring developed mosomes embedded in the nucleolar substance
centripetally into ac ell plate，a nd chloroplasts lined up on the equatorial plate. All four
and cytoplasm were divided into two cells chromosomes were rod-shaped and 5-6μm in
Figs. 11-12. Spirogyra crassa (n =12 ) 11-12. Te[ophase: 11. Fragmented chromosomes; 12. Newly
formed nucleoli.
Figs. 13-20. Spirogyra crassa X (n=6) 13-16. Prophase: 13-14. Two organizer tracks (arrows)
and six bead.shaped chromosomes; 15-16. Spindle formation and nuclear membrane (arrow) ;17 -18.
Metaphase: 17. Spindle and chromosomes enveloped with nucleolar substance; 18. Two N. O. chromoso.
mes (arrows); 19-20. Anaphase: 19. Parallel separation of chromnomes showing ladder-shape; 20.
Two daughter nuclei and dictyosomes (arrow). (Scale bars= 10μm).
6 HARADA， A. and Yf\ lvIAGISl ，Jl T.
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一 、 ー圃ーーー園田園 ...
，ヤ
Fig.2 1. Spi7'Ogyγa crassa X. 21. Metaphase. Six chromosomeS embedded in nucleo!ar substance
and dictyosomes (arrow).
Figs. 22-26. 5戸irogyrahunanensis (n= 4) 22-23.P rophas巴:22.T wo organizer tracks (arrow)a nd
chromocentrs;23. Four bead.shaped chromosomes;2 4-25.M etaphase: 24. Four chromosomes having
巴
bands; 25. Parallels parationof chromosomes; 26. Anaphase:26 . Symmetric arrangement of chromatids
巴
andd ictyosomes (arrow). (Scale bars=1 0μm)
length. The two N.O. chromosomes had a Densely stained chromocentersa nd nucleoli
satellite at their tips. Each chromosomeh ad in interphase nuclei are prominent features
clear bands (Figs. 24 and 25). At anaphase， of 5戸irogyra. GODWA RD (1956) mentioned
the nucleolar substance enclosing four chro- that the nature of the chromocenter was
mosomes spilt transversally into two. On regarded as a feature of cytotaxonomical
the chromatids of this stage，t h巴sameband- significance in Stirogyra. J-Iowever，v arious
ing pattern characterized metaphase chromo- forms of chromocenters，th read-or dot-shaped，
somes was observed (Fig. 26). wer巴 observedin each of the three speci巴S
investigated， and of the other species used
for coromosome observation (HARADA and
Discussion
YA MAGISHI， in preparation). Thus，a c1ear
Through the present study on three species， specificity of the chromocentersc an not be
S. crassa，S . crassa X and S. hunanensis，a recognized. GODWA RD( 1950，1 956)s uggested
general mitotic cycle of Stirogyra can be that the number of nucleoli and the organizer
shown in diagramaticf orm (Fig. 27). tracks in each nucleusw as related with the
Mitosis in Spirogyra (Chlorophyceae) 7
A B C D
H
Fig. 27. Diagram showing mitosis in Spirogyra. A. Interphase; B-C. Prophase; D. Metaphase;
E-G. Anaphase. bipartition of chromosomes enclosed with the nucleolar substance; H-I. Telophase.
(c: cytoplasm，p : pyrenoid，c p: chloroplast，n : nucleus，n l: nucleolus，c c: chromocenter，o t: organizer
track，s f: spindle fiber，n s: nucleolar substance，s t: satellite，n or: nucleolar organizing region，n oc:
nucleolar organizing chromosome，d : dictyosome).
number of the N.O. chromosomes. Through over，i t was confirmed that the number of
the observation of the three species，it is bands on each of the four chromosomes is
confirmed that the number of the nucleoli equivalent to the numbers of chromocenters
coincides with the number of the organizer appeared in early prophase in S. hunanensis
tracks. (Figs. 23 and 24).
GEITLER (1930， 1935) and DORAISWA MI GEITLER (1935)五rstdescribed the nucleolar
(1946) reported that all of the chromosomes substance in Spirogyra. DORAISWA MI (1946)
originated from the karyoplasm in Spirogyra. also suggested that the nucleolus changed
However，it was observed that all of the into as ubstance，c alled the granullar homo-
chromosomes except the N.O. chromosomes genous substance，i n midprophase. In Siro・
were formed from the iinearly arranged gonium (Zygnemataceae)，a s imilar substance
bead-like chromocenters in the karyoplasm， was also reported by WELLS (1969) and
as mentioned by WISSELINGH (1900) and HARADA (1981). GODWA RD (1953) traced the
GODWA RD (1954). The banding pattern relationship of the nucleolus and the nucleolar
(Figs. 6，1 8 and 24) in the chromosomes at substance in S. crωsa. Figures 14-16 show
metaphase became clear in pretreated pre- that the nucleolus completely loses its sharp
paration by 1N HC1. The number of the outline，t hen changes into the nucleolar sub-
bands in each chromosome in metaphase is stance. During late prophase，al l the chro-
constant in three species investigated. More- mosomes are completely embedded inside the
8 HARADA，A . and YA MAGISHI，T .
nucleolar substance. This substance scatters nucleolar substance itself.
and changes its original form in the squashed Sometimes chromosomes in metaphase are
preparation of mid，a nd late prophase，a nd it connected to one another with sticky threads
remains only around the N.O. regions (Fig. at the terminals or the sides. At anaphase，
5)，a s GODWA RD mentioned. each chromosome shows a ladder shaped
WISSELINGH (1900) and GEITLER (1930) ob- chromatic figure at the beginning of separation
served the N.O. chromosomes in some species (Figs. 8 and 19). GEITLER (1930) first ob-
of Spirogyra. GODWA RD (1950，1 953) illus- served the stickiness between the chromosomes
trated ag radual emergence of the organizer in S. crassa. Moreover，G ODWA RD (1950，
tracks and development of the N.O. chromo- 1953，19 54) mentioned that the sticky matrix
somes in S. crassa. Throughout this in- was the nucleolar substance itself. By the
vestigation from eariy prophase to metaphase staining method used in this study，t he chro-
in the three species，it is demonstrated that mosomes are distinguishable from the nucle-
the process of N.O. chromosome formation olar substance or nucleolus by their staining
agrees with GODWA RD'S observations. More- ability. After pretreatment with 1N HC1，
over，t he existence of the N.O. regions in the staining ability of the chromosomes de-
the nucleolus was ascertained by the pre- creases in contrast to the nucleolar substance，
treatment with 1N HC1，w hich decreased the which is never stained. By this method，
staining ability of the nucleolus (Fig. 5). chromatic strands or sticky threads between
GEITLER (1930) and GODWA RD (1953) reported the chromatids and the chromosomes are
the existence of as atellite of the N.O. chro- stained in the same degree as the chromo-
mosome which projected from the nucleolar somes. Judging from the staining ability，it
substance. In this study，t he satellite at is considered that the sticky threads and
metaphase was observed as a horn-shaped sticky substance are composed the S9.me sub-
projection. Moreover，it was confirmed that stance as the chromosomes.
the satellite does not slough off and is com- WISSELINGH (1902) observed that the spindle
pletely enclosed in the nucleolar substance did not develop to extend to the karyoplasm
(Figs. 6a nd 18). through the nuclear membrane in S. setiformis.
GEITLER (1930) first mentioned the parallel The spindle formation was also investigated
separation of chromosomes in S. crassa，a nd in detail by GEITLER (1930， 1935) and
he attributed this to the fluidity of the spindle DORAISWA MI (1946). Spindle formation was
and the rigidity of the chromosomes. observed in S. crassa X (Figs. 15，1 6 and 17)
GODWA RD (1954) considered that the separa- in material stained but not squashed，b ecause
tion of the chromatids was due to the fact the spindle loses its structure in squashed
that the chromosomes had polycentric or preparations. The process of spindle forma-
diffuse centromeres instead of a localized tion is similar to that described by GEITLER
centromere. The barrel-shaped spindle and (1930) for S. crassa.
the parallel separation of the chromosomes Cells which entered into division always
are observed in the three species used in this had ac ircle of minute granules (Figs. 20，21
study，a s has been reported by the previous and 26)，c alled dictyosomes (WELLS 1969)，
workers. When the chromatids separate in at the area where the new wall is formed.
parallel and move to opposite poles，t he chro- These organelles were also observed in
matids hold the same position and the same Sirogonium by HARADA (1981)，a nd in Zyg-
shape in each daughter nucleolar substance nema by HARADA and YA MAGISHI (1980).
in polar view (Figs. 9，2 0 and 26). This
phenomenon may mean that the chromosome
References
itself does not divide into two chromatids，
but that the parallel separation of the chro- DORAISWAMI，S. 1946. Nuclear division in Spi-
mosomes may be due to the separation of the rogyra. ]. Indian Bot. Soc. 25: 19-36.