INHERITANCE IN ASEXUAL REPRODUCTION 



171 



cessive intervals of two days furnish the basis of the graph. 

 The general trend of both lines is upward, although more mark- 

 edly so in A than in D. The same relation for the two clones 

 was found for the increase in the number of tentacles of the 

 parents (fig. 1). The increase in the parental number of ten- 

 tacles with age is due to some internal factor. Its relation to the 

 increase in the number of tentacles of successive buds will be 

 considered later. Besides this internal factor, there are various 

 environmental agents which modify the number of tentacles of 

 parent and bud in the same direction, and which must be taken 

 into account in any study of inheritance. 



Effects of starvation. One hundred polyps from a mass culture 

 of a single clone (clone A) were divided at random into two 

 groups of 50 each. One group was fed every second day with 

 small Crustacea, the other every sixth day. Both were placed 

 in clean dishes of fresh water every second day, and each polyp 

 was kept in a separate dish. The result of this method was 

 that one group received about three times as much food as the 

 other. The first result of the partial starvation of the six-day 

 group was a reduction in the rate of budding. The well fed 

 group produced an average of 0.203 buds per day for each polyp; 

 the starved group produced only 0.074 buds per day, which gives 

 a ratio of almost three to one, corresponding to the amount of 

 food given. There was also a difference in the average number 

 of tentacles of the buds produced by the two groups, the offspring 

 of well fed parents having a slightly higher average than the 

 others. This is shown in table 8. The difference here is small 

 and may easily have been due to chance. The experiment was 



TABLE 8 



Effects of starvation of parents upon the mean number of tentacles of their buds; 

 all buds recorded within 24- hours after their release 



