VAUCHERIACEE, 119 
In great number (20, 30, or more) they enter the neighbouring orifice 
of the sporangium, which they fill almost entirely, penetrating through 
the portion of the cutaneous layer remaining, whica, though without 
any definite boundary, offers a solid resistance to their further penetration 
into the sporangium. The corpuscles continue thus to struggle forwards 
into the cutaneous layer for more than half an hour, bounding against 
its outer surface they retreat, again push forwards, again retreat, and 
so on, in an uninterrupted succession of assaults and retreats. 
After this commotion has lasted some time, an abrupt boundary line 
suddenly appears in the outer aspect of the cutaneous layer, the first 
indication of a tunic forming around the contents of the sporangium 
which were before bare. From this moment the mobile corpuscles are 
separated from the cutaneous layer by a membrane which effectually 
prevents their further action upon the contents. They continue, it is 
true, to move to and fro, and this movement often lasts for hours 
together, but at last they perish in the rostrum itself. Even after the 
lapse of several hours the dead corpuscles may be seen in the rostrum, 
lying on the front of the sporangium, until at last they are completely 
dissolved, and all vestige disappears. 
The cutaneous layer surrounding the green contents of the sporangium 
becomes transformed, after impregnation, into the coat of the true spore, 
which, thus formed, represents a large cell occupying the whole of the 
sporangium, surrounded on all sides by the persistent tunic, which is 
open in front and prolonged into the rostrum. 
In this condition the spore remains for some time longer without being 
thrown off from the parent tube on which it was produced, but the 
colour of its contents gradually becomes paler and paler. The spore is 
at last rendered quite colourless, and presents in its interior only one or 
more largish dark brown bodies. When it has lost all colour it is 
detached from the parent tube, in consequence of the decay of the 
membrane of the sporangium enclosing it. After some time, say three 
months, the spore suddenly resumes its green colour, and immediately 
penipen grows into a young Vaucheria exactly resembling the parent 
plant. 
An abstract of the memoir from which the above details were obtained 
was published in the “ Quarterly Journal of Microscopical Science” for 
1856. (Vol. iv., p. 63). 
During the present winter Mr. Frederic Bates, of Leicester, has called 
our attention to some plants of V. sessilis, taken from beneath the ice 
in a pool, The first feature which presented itself was the septation of 
the threads, many of them being divided into numerous articulations 
three or four times the length of the diameter inthe upper portion of the 
thread, but longer below. This unusual septation, as it appears to be, 
was general throughout the gathering, but the threads bearing oogonia 
were more rarely divided, but sufficiently so to remove any doubt as to 
the threads being genuine threadsof Vawceheria, which at first we must 
confess to have doubted. The question which next arose was as to the 
purpose for which this septation had taken place, and an answer sug- 
gested itself in the collection of the cytioplasm into denser masses 
towards the centre of the cell, with most evident differentiation into oval 
bodies, resembling zoogonidia in course of formation. The time of 
observation has been short, but long enough to raise a suspicion in our 
minds that another form of fructification, by means of zoogonidia, takes 
place in Vaucheria, and the occurrence of germinating spores in various 
early stages in the water in which the Vaucheria was being preserved, 
lends strength to this suspicion. It is quite true that Vaucheria has 
been often and patiently studied, and no intracellular swarm-~spores 
detected ; yet it may be possible that, under certain conditions, they may 
be produced. We are patiently waiting in hopes of obtaining active 
zoogonidia, 
8 
