MONSTROSITIES 293 



vertebrates, may be the reason why so many strange monster-like 

 forms are found among these animals. 1 



It might be thought incredible that a monstrous form could 

 pair with a normal form. It would all depend, as I said, upon 

 whether the sperm cell of the one could be made to reach the 

 germ cell of the other. By artificial means Messrs. Veitch and 

 Son have succeeded in mating a Lcelia with a Sophronitistwo 

 forms of orchids which no botanist would have conjectured are 

 mere variations of the same species \ 



This is not all, for Professor Agassiz 2 says, ' I remember to have 

 found in the neighbourhood of .Mobile (U.S.), no less than six new 

 species in the course of an afternoon ramble. These fishes are 

 almost all viviparous, or at least lay their eggs in a very advanced 

 state of development of the young. 3 The sexes differ so greatly 

 in appearance that they have sometimes been described as distinct 

 species, nay, even as distinct genera (Molinesia and P<zcilia}, We 

 must be on our guard against a similar mistake.' . 



If husband and wife of these fishes can be so distinct as to be 

 described as distinct species and genera, and still pair, what wonder 

 would it be if monstrous forms, produced by disturbing influences 

 which may have occurred during the first stages of embryonic 

 development, should be able to pair with their normal progenitors, 

 although, may be, quite distinct in anatomical characters ? 



At one time there was a dogma among biologists that animals 

 of different species could not interbreed, as, if they happened by 

 some chance to interbreed, their progeny was barren. It was 

 thought perhaps that some providential law ruled matters thus, in 

 order to prevent the mixing of species. But now it seems to be 



1 The variations of type in the Fishes of the Amazon, noted by Professor L. Agassiz, 

 are simply innumerable. 2 Journey in J^razil^ pp. 32, 33. 



3 He does not mention how their ova are fertilised. 



