igos.j JENNINGS— HEREDITY IN PROTOZOA. 471 



condition, including representatives of the small, starving condition, 

 the well grown condition, and intermediate states ; it is a sort of a 

 resume of the variations due to nutrition. If we add together the 

 tables given by the starving culture (earlier than Table XX.) and 

 the two well-fed cultures (later than Table XX.), we get a collection 

 of 450 individuals, in which the variation in length and breadth is 

 about the same as for Table XX. (see row 12, Table XVIII. ). For 

 Table XX. the coefficients of variation for length and breadth ar? 

 12.767 and 28.879; the corresponding coefficients for the three lots 

 combined are 13.795 and 27.184. 



Although the animals are all descended from the same parent and 

 have lived under the same conditions save for the ten days during 

 which these experiments lasted, we find that in the period just men- 

 tioned the polygons of distribution of variations in length have so 

 changed that the one for the end of the ten day period (11, Diagram 

 6) hardly more than overlaps at one end that for the beginning of 

 the period (8, Diagram 6). 



Addition of fresh hay infusion causes in these cases an increase 

 in length, in breadth, in variation, and in the correlation between 

 length and breadth. But whether these results shall follow depends 

 upon the previous condition of the animals. This is illustrated by 

 the fact that there is one exception to the statement just made; the 

 variability in breadth decreased in place of increasing in the transi- 

 tion from Table XXI. to Table XXII. The efifect of the previous 

 condition is better seen in the experiments of the third series, to be 

 described next. 



Third Scries. 

 A culture of the descendants of D was rather ill-fed, though not 

 starving; the animals were long and slender (Fig. 6, a and b). Half 

 of these were allowed to remain in the old fluid, while half were 

 placed in fresh hay infusion. After forty-eight hours, a random 

 sample of each set was measured. Tlie measurements of the set in 

 the old fluid are given in Table LIV., the constants in row 13, Table 

 XVIII. The results of keeping the animals forty-eight hours in the 

 fresh infusion are shown in Table LV., and in row 14, Table XVIII. 

 The animals grew plump and multiplied ; the mean breadth increased 



