332 



The Study of Animal Life part iv 



interesting to learn that colour-blindness has been known 

 to occur in the males only of six successive generations, 

 deaf mutism for three, finger malformations for six, and so 

 with harelip and cleft palate, and with tendencies to con- 

 sumption, cancer, gout, rheumatism, bleeding, and so on. 

 Ikit these facts do not prove the transmission of functional or 

 environmental variations ; they only corroborate what every 

 one allows, that innate, congenital, constitutional characters 



Fig. 70. — Half-lop rabbit, an abnormal variation, which by artificial selection 

 has become constant in a breed. (From Darwin.) 



tend to be transmitted. Yet some cases recently stated by 

 Prof. Bertram Windle seem to suggest that some patho- 

 logical conditions acquired by function may be transmitted. 

 But even if a non-constitutional pathological state acquired 

 by a parent reappeared in the oiit'spring, we .require to show 

 that the offspring did not also acquire it by his work or 

 from conditions of life, as his parent did before him. 



(3) Some individual cases seem to stand some criticism. 



Two botanists, Hoffmann and Detmer, have noted such 

 facts as the following — scant nutrition influenced the flowers 

 of poppy, Nigella^ dead-nettle, and the result was trans- 



