342 Organic Nature s Riddle 



shown by the need of the repetition of circumcision, and of 

 pressure of Indian children's heads and Chinese girls' feet, 

 in each generation. Yet there is good evidence that such 

 changes are occasionally inherited. The epileptic offspring 

 of injured guinea-pigs is a case often referred to. Haeckel 

 speaks of a bull which had lost its tail by accident, and 

 which begot entirely tailless calves. With respect to cats,^ 

 I am indebted to Mr. John Birkett for the knowledge of an 

 instance in which a female with an injured tail produced 

 some stump-tailed kittens in tAvo litters. 



There is evidence that certain variations are more apt 

 to be inherited than others. Amongst those very apt to be 

 inherited are skin affections, affections of the nervous system 

 and of the generative organs, e.g. h3rpospadias and absence 

 of the uterus. The last case is one especially interesting, 

 because it can only be propagated indirectly. 



Changes in the environment notoriously produce changes 

 in certain cases, even in adults. The modifications which 

 may result from the action of unusual agencies on the 

 embryo have been well shown by M. C. Dareste.^ As has 

 been already remarked, processes of repair take place the 

 more readily the younger the age of the subject. Similarly, 

 it is probable that the action of the environment generally 

 acts more promptly and intensely on the embryo than in 

 the older young. That the same organism will sometimes 

 assume very different forms has been observed by Professor 

 Lankester in the case of Bacterium rnfescens? 



The effects of changed conditions is often very striking. 



1 See The Cat (John Murray, 1881), p. 7. 



2 See Archives de Zool. Exper. vol. ii. p. 414, vol. v. p. 174, vol. vi. p. 31 ; 

 also Ann. des Sci. Nat. No. 4 seVie, Zoologie, vol. iii. p. 119, vol. xv. p. 1, 

 vol. xvii. p. 243 ; and his work Hecherches mr la Production artijicielle den 

 Monstruosites ou Essais de Teratogenic cxperimentale. 



^ See Quarterly Journal of Micros. Soc, New Series (1873), vol. xiii. 

 p. 408, and vol. xvi. (1876) p. 27. 



