INDUCED CHARACTERS IN ASPLANCHNA AMPHORA 367 



In order to test further the nature of H and / in regard to their 

 latent potentiaUty to produce the higher type, derivative mass 

 cultures were started from time to time, it having been proven 

 by all our previous experience that mass cultures favor the pro- 

 gressive mutation to the larger types. Irregular food supplies 

 were purposely resorted to in these cultures as favorable to the 

 transition. Transitions did indeed occur to the humped type, and 

 in a few instances cannibalistic campanulates also 'made their 

 appearance. This latter transition, however, was far less frequent 

 than in parallel mass cultures derived from J and K. 



The natural conclusion suggested by the conduct of the above 

 series is that we do have the transmission of experimentally 

 induced factors through the sexual gametes and the resulting 

 resting egg. While this result is not shown morphologically in 

 the generation immediately derived from the zygote yet it would 

 seem to plainly exist as an inherent factor, the factor which we 

 have termed the physiological potential. 



In order to accumulate further evidence for the fact of this 

 transmission and also to ascertain whether such transmission is, 

 as it were, a uniform process or whether it may perhaps be variable 

 or cumulative, or regressive, we continued the rearing of further 

 series derived from resting eggs produced by the same stocks. 



As the labor of rearing these stocks is very considerable and we 

 wished to mass abundant proof upon the points tested we choose 

 to limit the work to inbred series only. 



Series derived by inbreeding individuals of I and J 



It may be first explained that owing to the diverse inherent 

 tendencies of reproduction it was easy to obtain resting eggs 

 from humped series like J while it was a matter of much difficulty 

 to obtain them from saccate series like /. It was thus not feasible 

 to begin a new parallel series of these two types simultaneously. 

 Adequate centrols however were always conducted. To test the 

 inheritance of the high potential of J new series were derived as 

 follows: On January 15, during the twenty-first generation of J, 

 a mass culture was obtained from the fourteenth daughter of the 



