INHERITANCE IN ABNORMALITIES 391 



this was impossible because of the rapid movements of the ani- 

 mal. For about two weeks after conjugation camera lucida 

 drawings were made of the abnormal forms. These were often 

 less active than the normal forms and after being in the same 

 drop of culture fluid for two days all of the individuals were 

 more or less sluggish. So with a little patience camera lucida 

 drawings could be obtained of almost all the abnormals. When 

 the number to be examined and drawn became very large, how- 

 ever, there was no time for that procedure and free hand draw- 

 ings were made in the majority of cases, camera lucida only in 

 such cases as seemed of more than ordinary interest. The slide 

 cultures were examined every other day during the cool weather, 

 every day when it became very warm, the individuals counted, 

 the abnormals drawn, selection made of those by which the 

 slide cultures should be carried on, and the others put into the 

 bottle mass-culture corresponding to that race. The individuals 

 selected for slide culture were then washed in the milk solution, 

 and put into fresh fluid on clean slides. 



III. EXPERIMENTAL CULTURES 



The material presented in this paper is derived from three 

 experimental cultures carried from the fall of 1912 to the spring 

 of 1914. The first experiment, conducted from December 2, 

 1912, to June 11, 1913, was carried out with exconjugant mem- 

 bers of a wild population which doubtless included members of 

 many diverse stocks. The chief aim of this first experiment was 

 to ascertain whether or not abnormalities were ever inherited, 

 and to what extent. From November 25, 1913 to December 

 22, 1913, a second experiment was conducted on a group of 

 animals all descended from one individual, constituting there- 

 fore a 'pure line' or 'clone.' It was concerned mainly with deter- 

 mining the efl"ect of conjugation among the members of a single 

 clone, particularly as to the production of abnormalities; this 

 was brought out by a comparison of exconjugants with mem- 

 bers of split pairs belonging to the same clone. In the first 

 experiment some work on the effect of selection was attempted; 

 but the third experiment, carried out on a wild population from 



