204 Heredity and Eugenics 



might be duplicated and extended by proper experimentation 

 with other plants and lead to new and important informa- 

 tion. A biotype of Capsella, bursa-pastoris, much like 

 taraxicafolium, lives on the low plains along the coasts of 

 Asia Minor. It has broad leaves, white flowers, and grows 

 to 30-40 cm. high. On the inland plateau at altitudes of 

 2,000-2,500 meters grows another form with a stem 2-5 cm. 

 high, reddish flowers, xerophilous leaves, and an elongated 

 root system. 



From the lowlands roads lead to the plateau, and the 

 conditions of distribution are such as to suggest that man 

 has been influential in disseminating this form from the 

 lowlands to the highlands, where it has taken on the modi- 

 fied form. Some force to this interpretation of the dis- 

 tribution is given by the fact that seeds from the plains, 

 when taken to the plateau, at once assume the somatic 

 characters of the plateau type. On the other hand, plateau 

 seeds, planted and grown at Vienna, while they have the 

 xerophilous character of the leaves, retain the upland char- 

 acters in flowers, and, to a large extent, in height, root 

 system, and general habit. It is futile to attempt to draw 

 from observations in nature such as this conclusions as to 

 the past history or actual happenings, but such instances 

 clearly indicate the sort of experimentation that might 

 profitably be attempted and the type of results that might 

 be expected. 



Much more concrete and accurate are the findings of 

 Klebs upon Sempervivum, in which inflorescences were 

 found to be capable of replacement by a single flower, and 

 many other changes were induced as the result of external, 

 mainly climatic, forces. More important than the fact 

 of the departure is the fact that some changes persisted 



