Inheritance of Acquired Characters 21 



from the original type. If such a type were established, 

 of course its germ plasm would produce alpine plants, 

 even in lowland conditions. They might not survive 

 long and natural selection might eliminate them, but 

 their structure would be due, not to the inheritance of 

 somatic structures, but to the inheritance of an alpine 

 germ plasm. 



If corn is planted in poor soil weak individuals 

 result. Seed from these weak individuals, when planted 

 in good soil, will develop again somewhat weakened 

 individuals, and this suggests the inheritance of acquired 

 characters. In fact, however, it is merely the direct 

 effect of environment continuing through the second 

 generation. The weak individuals in the poor soil 

 develop small seeds with low nutritive capacity, and 

 plants developed from abnormally small seeds are always 

 weak, whether the individual that produced the seed grew 

 in poor soil or not. 



In 1909 Mayr (4) wrote a notable work on silvicul- 

 ture in which he claimed that only species characters are 

 inherited in trees, and that the effects of cUmate are not 

 inherited, and therefore that the source of the seed 

 makes no difference. In other words, seeds of Scotch 

 pine would always produce Scotch pine progeny, 

 no matter at what latitude or altitude the ancestors 

 had been growing. According to Mayr, therefore, 

 there is no inheritance of acquired characters in 

 trees. ' " 



In 1912, however, the United States Committee on 

 Breeding Nut and Forest Trdes'(5) came to the con-' 

 elusion that the source of seed is of great importance. 

 This conclusion was based chiefly upon the testimony 



