310 Scientific Intelligence, [no. 4, new series^ 
tractibillty to execute the most varied movements. These sper- 
matozoids so soon as they are able to disperse themselves in the 
cavity of the Volvox, quickly crowd around the female cells into 
which they eventually penetrate ; arrived there, they attach them- 
selves by the beak to the plastic globule, destined in each cell to 
form a spore, and with which they are gradually incorporated. 
Fecundation having been thus effected, the reproductive globule 
becomes enveloped successively by an integument exhibiting coni- 
cal pointed eminences and by an interior smooth membrane ; the 
chlorophyll which it contained is now replaced by starch grains and 
a red or orange coloured oil. Thisis the conditioij of the spore at 
maturity and occasionally forty of these bod,'es may be counted 
in a single globe of Volvox. The germination of these reproduc- 
tive bodies has not yet been observed, so that their history cannot 
be regarded as complete : but from analogy it may, in the mean- 
■while, be assumed that they germinate in the same way as do the 
spores of /Edogoniiim Sphoeroplea, and other Algce belonging to 
the same order. It may be maintained moreover, as certain 
that the Sphoerosira volvox, Ehr., is nothing else than a monoe- 
cious Volvox glohator ; that his Volvox stellatus is also V. glo- 
hator, observed at the time when it is filled with stellate spores, 
and, lastly, that the V. aureus of the same author differs from 
the other forms of the same species, simply in the smooth [and 
coloured] condition of the spores." — Journal Microscop. Society , Vol. 
Y,page 149, No. XIX for 1857. 
It must be added that Professor Cohn is by no means the first 
discoverer of the true nature of the Volvocince. 
At the meeting of the iNIieroscopic Society of London on the 
26th May 1852 a paper on " ihe structure and development of 
Volvox glohator and its relations to other unicellular plants" was 
read by Mr. George Busk, F. R. S. followed by a copious Appen- 
dix inthe*^Oct. of the same year. Between which Professor William- 
son also submitted a paper on " the farther elucidation of the 
structure of V. glohator^' at the meeting of the 21st June. These 
papers which go into the subject at great length are of too techni- 
cal a character to suit the purpose of this Journal. 
