r 
qt CRITICISMS ON “THE ORIGIN OF SPECIES” 97 
_ always,as we have seen, A: B: A: B, &c. ; whereas, 
' for the production of a new species, the series must 
be A: B:B:B, &c. The production of new species, 
or genera, is the extreme permanent divergence 
from the primitive stock. All known Agamo- 
genetic processes, on the other hand, end in a com- 
_ plete return to the primitive stock. How then is 
the production of new species to be rendered 
intelligible by the analogy of Agamogenesis ? 
The other alternative put by Professor Kolliker 
—the passage of fecundated ova in the course of 
their development into higher forms—would, if it 
occurred, be merely an extreme case of variation in 
the Darwinian sense, greater in degree than, but 
perfectly similar in kind to, that which occurred 
when the well-known Ancon Ram was developed 
from an ordinary Ewe’s ovum. Indeed we have 
always thought that Mr. Darwin has unnecessarily 
hampered himself by adhering so strictly to his 
favourite “ Natura non facit saltum.” We greatly 
suspect that she does make considerable jumps in 
the way of variation now and then, and that these 
saltations give rise to some of the gaps which ap- 
pear to exist in the series of known forms. 
Strongly and freely as we have ventured to 
disagree with Professor Kélliker, we have always 
done so with regret, and we trust without violating 
that respect which is due, not only to his scientific 
eminence and to the careful study which he has 
VOL, II H 
