EMBRYOGENY 203 



greatly altered. If, now, after some vegetative periods 

 the seed of such purposely adapted ' alpine ' plants be 

 sown again in the valley, there is shown in the resulting 

 individuals a strong tendency to retain the ' adaptive 

 characters/ 



Obviously in this case the formation of the seed 

 (the embryo) alone was under the influence of the 

 elevated position : the entire growth of the plant 

 itself occurred in the valley. What, therefore, still 

 appears of the alpine character and that in the first 

 generation is fairly considerable was established in 

 the seed (embryo) and therefore already in the ovum. 



In other words, the entire embryonic development 

 is so fashioned that it no longer strives towards the 

 earlier forms but rather towards the newly acquired 

 adult ones. 



This applies exactly to the other cases : if the 

 alterations which mostly appear in the full-grown 

 complete forms have arisen by parasitism, by 

 particular modes of life, by isolation, etc., the embry- 

 onic development is always influenced ; if it were not, the 

 changed adult forms could not present themselves at all. 



The deeper the transformation of the entire organism 

 may be which it needs in order to become adapted to 

 its new mode of life, the greater will its embryonic 

 evolution differ from the earlier one. The more trifling 

 it is, the less also will the embryogeny be altered. 

 Furthermore, there are visible the alterations, in those 

 germ stages in which the organs commence to form, 

 which are specially designed for service under the 



