172 SEXUALITY AMONG THE CONJUGATS. 
— + Flores involucello destituti. 
63. M, nusicena = Malva nubigena Wedd. Chlor. And. ii. p. 276. 
Sida nubigena Walp. in Nova Acta, xix. Suppl. i. p. 507. 
Hab. Peru Bolivia, Mandon 
va M. Ontstrum = Malva Disdeicion Wedd. Chlor. And. ii. 
| 48 
Hab. Bolivia, prov. Cinti, Weddell. 
The last two plants I have not seen, and possibly they may not 
belong to the genus Malvastrum. 
(To be continued.) 
SEXUALITY AMONG THE CONJUGATE. 
By Aurrep W. Bennett, B.8c., F.L.S. 
or many years maintained, in opposition to the views of 
ist t 0 
‘‘ conjugation in the Zygnemacea, the higher order of the Conjugate, 
is a sexual one: the filaments, where the conjugation is ‘‘ scalari- 
form,” ee always differentiated into male and female. Will you 
allow me to call the attention of those of your readers who are 
interested in the subject to three memoirs, all very recently pub- 
lished, which strongly confirm the view I have taken, and, etry 
may almost be regarded as setting the question at rest :—‘‘ Hin 
Notiz tiber das Verhalten der Chlorophyll-bander in den ictal 
der Spirogyra-arten,’’ in the Botanische Zeitung for 1890, No. 28, 
by Herr V. Chmielevsky; “ Zur Kenntniss der Conjugation bei 
Spirogyra,” in the Sitzwngsberichte of the Vienna Academy of 
Sciences, vol. xcix., Heft. 6 & 7, by Dr. G. Haberlandt; and ‘Sulla 
conjugazione delle Zignemse: in Neptunia for Feb. and March, 
1891, by Mr. W. Wes 
Herr Chmiele ey ‘has established the ogee fact, from 
observations made on several species of Spirogyra and Rhynchonema, 
be 
s of the ‘“‘male” and those of the “female” c ell, and that 
shhage of the latter always exhibit a more regular spiral than those 
of the former. Hven r complete conjugation, the fhe wealth 
band always retains its green colour, while the “male” b and tu 
yellow and becomes disorganised, finally becoming absorbed nto 
the protoplasm of the cell. This is equally the case whether the 
conjugation be ‘* scalariform”’ or ‘lateral’; in the latter case a 
‘male’ ree erage lies nearer to the conjugating canal. 
te contains a single nucleus and a varying agudber 
of chlorophyll heidi, but pees th the same number as those in the 
* female ” ae which remain 
nged in the zygote 
to Prof. caieuit the contraction of the Mirador 
of the se poate cell, and its conversion into a gamete, 
result of an excitation exerted on it by the male cell. The male” 
and ‘ female”’ filaments, indeed, appear to exert a mutual excitation 
_ onone another. The two conjugating tubes are not always formed 
