Address of the President at the Annual Meeting, 53 
in deep obscurity ; for it can scarcely be doubted that many of 
the animalcule-like bodies, such as the Volvocince, whose 
vegetable nature has been made known to us by observation 
of certain stages in the history of their lives, are but the 
motile forms (zoospores) of some other plants, whose relation to 
them is at present unknown. Hitherto it has been commonly 
thought sufficient to trace the history of any of these bodies 
from their first production by binary subdivision, or some 
essentially-equivalent process (gemmation), to the repetition 
of the same process by themselves, which was considered as 
terminating their life as individuals ; and neither was any 
departure from this simple plan of reproduction, nor the 
origination of a new and dissimilar form in any part of the 
series, at all anticipated. But now that we have juster views 
of the real analogies (or, more properly, homologies) of these 
simple plants, it becomes evident that the multiplication of 
cells by binary subdivision, or by any kind of outgrowth, 
really corresponds with the multiplication of elementary parts 
in the embryo of any one of the higher plants or animals ; 
and that the almost indefinite increase which may thus take 
place, is really the growth of the individual, which will at last 
take on a new phase, sexual organs being evolved, and a true 
process of generation (essentially consisting in the reunion of 
the contents of two cells, by conjugation, or some equivalent 
act) being performed by their instrumentality. The life of 
the individual, as I long since maintained, and as is now coming 
to be generally admitted, includes the whole series of pheno- 
mena which intervene between one act of generation and 
another ; and this series of phenomena may include the pro- 
duction of two or three very distinct and apparently unrelated 
forms. Hence until we have traced out this history in regard 
to every distinct type of animal and vegetable life, we must 
not only consider our knowledge of it to be essentially incom- 
plete, but we must also admit the probability that a vast 
number of our reputed species have no real existence. Many 
distinguished German and French obsiervers* have recently 
been devoting themselves to this kind of inquiry, singling out 
a few specific forms, and endeavouring to trace these through 
all their phases of development ; and the success which has 
already attended their endeavours, is the best encouragement 
to more extended labours in the same direction. 
* See especially the Memoirs of Professor Stein, in * Weigmann's 
Archiv.,' and in ' Siebold and KoUiker's Zeitschrift,' and his recently- 
published work, * Die In fusion sthiere,' which embodies the preceding ; 
also M. Jules Haime, on TricJioda lynceus, in * Ann. des Sci. Nat.,' 3* S^r., 
Zool., tom. xix. 
