INHERITANCE IN HYDATINA 53 



families showing low and high viability, respectively, and from 

 them the lines designated L-i and Ho were reared. 



Each of these lines was inbred, and the fertilized eggs desig- 

 nated Ls and H^ were secured. L2 and H^, were also crossed 

 reciprocally (L2 X Ho and Ho X L^), but no parthenogenetic 

 lines were reared in these cases; viability was determined and 

 the eggs discarded. 



From this point the low viability and the high viability series 

 may be followed separately. The line bred from the eggs named 

 L3 was again inbred, the eggs being marked Lj. Two families 

 of these eggs were selected, one for low, the other for relatively 

 high viability. From each was reared a new line, each of which 

 was inbred to produce a batch of fertilized eggs (L from L, and 

 H from L). With these eggs the experiments with the low via- 

 bility series terminated. 



Of the lot of eggs in Hz, two families were selected, one show- 

 ing relatively low, the other high viability; from each a line 

 was started. These parthenogenetic lines were inbred to pro- 

 duce the lots of eggs called Li from H, and Hi from H. Selec- 

 tion of families for low and high viability, respectively, was made 

 in these lots of eggs and a parthenogenetic line bred from each. 

 These lines were in turn inbred, the fertilized eggs being 

 designated L2 from H, and H2 from H. With these eggs the 

 experiments in the high viability series terminated. 



DETAILS OF THE EXPERIMENTS 



The following account of the individual experiments is divided 

 and labeled in accordance with the diagram in figure 1, in con- 

 nection with which the description may be easily followed. 



A. The data for this line were published in part in a former 

 paper. It comprised 55.2 per cent of male-producers. 



B. This line was likewise given in an earlier publication. It 

 included 16.5 per cent of male-producers. 



C. The resting eggs of this lot were obtained by mating females 

 with males of line A on June 28 and 29, 1911. These females 

 laid on the average 8 eggs apiece. The eggs were dried soon after 

 laying, and remained in this condition until August 31, 1911, 



