258 E. RAY LANKESTER, ON THE 
impossible to say; at any rate, for ought we know to the 
contrary, it may be also formed during the growth of the 
gonidium of lichens, and it would seem rash at our present 
state of information to confine it within any limits. Further 
observations are wanting before we can consider it peculiar 
to the Conferve. 
The same remark may be applied to the zoospores, the 
formation of which is also asexual process. We have evidence 
which shows that the formation of zoospores extends over 
a wider range than had formerly been believed. There, 
again, is a fine field here for observation. It is very possible 
that some of the Volvocineze may have an origin in some 
other form of life, especially since Cohn has shown forms of 
zoospores of Protococcus pluvialis, united in such a manner 
as to partake of many of the features of that tribe. No 
finer field than the one I have above pointed out is open for the 
patient observer, who will carefully trace, and as carefully 
portray, every step of the form in which he is interested. 
The Anatomy of the EartHworm. 
By E. Ray Lanxester. 
Part I. 
Brine desirous of publishing a notice of certain new 
points of structure which I have detected in the earthworm, 
I thought that it might be well to accompany it with a 
description of the general anatomy of that Annelid, espe- 
cially since the later and more accurate observations on this 
subject have been published as papers in foreign journals, 
and are scattered about in various French, Belgian, and 
German periodicals. The appearance too, of a paper in the 
‘ Philosophical Transactions’ for 1858, by Dr. Williams, in 
which the anatomy of the reproductive organs of Lumbricus 
is treated of, has been a further inducement to me to publish 
my observations on this point. The separate researches 
of two Continental naturalists, M. Jules d’Udekem and Dr. 
Ewald Hering, had placed our knowledge of the generative 
system of the earthworm in a so far satisfactory state that 
little more remained to be done than to explain a few minor 
. discrepancies between the results arrived at by these authors. 
Dr. Williams, however, having failed to observe that which is 
