Druce, on Confervoideae. 
77 
where the true generative act intervenes, as the phenomenon 
occurs in a class so highly organized as to afford us unmis- 
takeable ova and spermatozoa in their respective organs. 
Upon this plan there is nothing extraordinary in the occur- 
rence of spores in each cell of a Conferva (as in Spirogyra 
mirable, and Mougeotia notabilis), or in both ceils of a con- 
jugating filament, or in a cell to which the papilla has not 
reached that of the one opposite. And indeed, finally, I 
would say that there is not anything remarkable in any 
spherical aggregations of endochrome within cells, for their 
appearance is often the precursor of decay in injured fila- 
ments. So far we have had to deal with facts well ascertained, 
however open they may be to difiference of interpretation. I 
have now to present to you occurrences resting principally 
upon my unsupported observations. These, however, have 
assumed a consistency which, when coupled with my previous 
conviction that conjugation is not the true reproduction in 
Confervas, have made me deem these observations of sufficient 
importance to submit to your consideration. The late Pro- 
fessor Henfrey mentions, in the ' Micrographic Dictionary,^ 
as an abnormal occurrence in Spirogyra, the conversion of the 
endochrome in certain cells into large colourless zoospores ; 
this it has been my good fortune to witness in so many in- 
stances, that it is impossible to regard it otherwise than as 
connected with reproduction. It has also presented itself in 
(Edogonium, and the process is as follows, in both cases. 
The Chlorophyll vanishes by degrees from the cells, which 
become at last diaphanous ; though obviously still fall of cell- 
contents, the characteristic nucleus of Spirogyra is enlarged, 
and the protoplasmic threads thickened and connected with 
nucleus-like aggregations of protoplasm at the sides j nuclei 
and protoplasmic tln-eads not so definitely arranged, but 
still obvious, are to be seen in GEdogonium, and the contents 
at last break up into the large colourless zoospores above 
mentioned ; these grow in size, become spherical, and are 
gradually filled with a purplish black endochrome, which at 
last becomes dense, though evidently granular; and finally 
the capsules burst and discharge minute bodies, moving 
actively, into the cavity of the cell ; although my power of 
350 diameters was insufficient to detect any cilia. They most 
resemble the spermatia of lichens. This I believe to be the 
antheridial function in Spirogyra, and so far in all essentials it 
agrees with the account of Pringsheim on (Edogonium, 
excepting that the antheridial capsules discharge their con- 
tents before leaving the parent cell ; but the foregoing process, 
I have said, obtains also in (Edogonium, and is at first sight 
