INHERITANCE 723 



Table 14 from Moewus shows the number of days required for the 

 transformation to type 5, in relation to the number of days the organisms 

 had lived in peptone medium. In interpreting this table, it is important 

 to keep in mind the fact that reproduction occurs at about the rate of 

 one generation a day, or more rapidly. 



In the last examples of Table 14, it required a year and five months 

 in their new conditions to induce in the organisms the transformation to 

 type 5. During this period hundreds of generations were produced. The 

 longer the organisms remain in peptone culture as type 1, the longer it 

 requires for the new conditions to transform them to type 5. 



Moewus presents many other cases illustrating the same principle. 



The different types or varieties found in nature usually require a very 

 long period of culture in a given medium to induce them to transform 

 to the type characteristic for that medium. Thus a certain stock 4 was 

 found in nature as type 10, having no papilla. Placed in peptone culture, 

 it remains as type 10 for 450 generations, then the organisms begin to 

 transform to type 1, having a papilla; in time all transform to type 1. 

 The type 10 was seemingly a Daiiennodifikation in nature; it transforms 

 to type 1 only after many generations under artificial conditions. Moewus 

 describes many other cases in which types found in nature resist, for many 

 generations, changes due to new conditions, but finally transform into 

 types characteristic for the medium to which they are transferred. Thus 

 the indications are, as Moewus points out, that many of the diverse types 

 ("varieties") found in nature are in fact long-lasting modifications 

 resulting from the long-continued action of certain environmental condi- 

 tions. 



VARIATION AND ITS INHERITANCE OCCURRING WITHOUT OBVIOUS 

 ACTION OF DIVERSE ENVIRONMENTS 



In addition to inherited changes produced by diverse environments, 

 already described, there occur in some cases during vegetative reproduc- 

 tion inherited changes, without apparent action of diverse environments. 

 Such cases possibly differ in principle from those described above, illus- 

 trating the occurrence of inherited variations that are not brought about 

 by environmental action. If so, they are of much theoretical interest. 

 On the other hand, they may involve concealed action of diverse environ- 

 mental conditions, as urged by Jollos (1934). The phenomena are in 



