96 CRITICISMS ON " THE ORIGIN OF SPECIES " m 



No case of Agamogenesis is known in which 

 when A differs widely from B, it is itself capable of 

 sexual propagation. No case whatever is known 

 in which the progeny of B, by sexual generation, 

 is other than a reproduction of A. 



But if this be a true statement of the nature of 

 the process of Agamogenesis, how can it enable us 

 to comprehend the production of new species from 

 already existing ones ? Let us suppose Hyaenas 

 to have preceded Dogs, and to have produced the 

 latter in this way. Then the Hyaena will represent 

 A, and the Dog, B. The first difficulty that pre- 

 sents itself is that the Hyaena must be non-sexual, 

 or the process will be wholly without analogy in 

 the world of Agamogenesis. But passing over this 

 diffictilty, and supposing a male and female Dog to 

 be produced at the same time from the Hysena 

 stock, the progeny of the pair, if the analogy of 

 the simpler kinds of Agamogenesis 1 is to be fol- 

 lowed, should be a litter, not of puppies, but of 

 young Hyaenas. For the Agamogenetic series is 



1 If, on the contrary, we follow the analogy of the more com- 

 plex forms of Agamogenesis, such as that exhibited by some 

 Trematoda and by the Aphides, the Hyaena 'must produce, non- 

 sexually, a brood of sexless Dogs, from which other sexless 

 Dogs must proceed. At the end of a certain number of terms 

 of the series, the Dogs would acquire sexes and generate young ; 

 but these young would be, not Dogs, but Hyaenas. In fact, we 

 have demonstrated, in Agamogenetic phaenomena, that inevitable 

 recurrence to the original type, which is asserted to be true of 

 variations in general, by Mr. Darwin's opponents ; and which, 

 if the assertion could be changed into a demonstration, would, 

 in fact, be fatal to his hypothesis. 



