Adaptation to Environment 337 



experiments on Fundulus seem to indicate. If the 

 temperature rises too rapidly the damage cannot be 

 repaired quickly enough by the cell or body liquids. 



It is also to be considered that substances might 

 be formed in the body at a higher temperature which 

 do not exist at a lower temperature, and vice versa, 

 and this might explain results like those of Schottelius 

 or Dieudonne and many others. 



6. The theory of an adapting effect of the environ- 

 ment has often been linked with the assumption of the 

 inheritance of acquired characters. The older claims 

 of the hereditary transmission of acquired characters, 

 such as Brown-S6quard's epilepsy in guinea pigs after 

 the cutting of the sciatic nerve, have been shown to be 

 unjustified or have found a different and more rational 

 explanation. Recently P. Kammerer has claimed to 

 have proven by new experiments that by environmental 

 changes, hereditary changes can be produced. 



It has been mentioned already that the mature male 

 frogs and toads possess during the breeding season lumps 

 on the thumbs or arms which are pigmented and which 

 bear numerous minute horny black spines; these secon- 

 dary sexual characters serve the male frog in holding 

 the females in the water during copulation. There is 

 one species which does not possess this sexual character, 

 namely the male of the so-called midwife toad {Alytes 

 obstetricans). In this species the animals copulate on 

 land, and it is natural to connect the lack of this secon- 



