204 ROSCOE R. HYDE 



in regard to egg production whether the father or the mother of 

 the hybrid came from the low-producing truncate stock. 



In this experiment conditions were as uniform as possible. 

 The virgin females were in each case paired with three of their 

 brothers. The. eggs were counted each day with the aid of a 

 dissecting microscope and discarded. The females in this experi- 

 ment were given a chance to lay their eggs on dried apples that 

 had been soaked in water and allowed to become slightly sour. 

 This insures great accuracy in counting, as the white eggs are 

 easily seen against a brown background. 



The count as given in tables 21 and' 22 supports the conclusion 

 that the hybrid female has a greatly increased ouput of eggs as 

 compared with the Woods Hole female. Now despite the fact 

 that only about 56 per cent of her eggs hatch when tested with her 

 own male, yet she is able to produce as many if not more offspring 

 than her high producing parent, the fertility of which is 75 per 

 cent. We should expect the hybrid to lay approximately twice 

 as many eggs. An analysis of table 22 shows this to be true. It 

 is true that no far-reaching conclusion can be based on such a 

 round-about treatment as this, taken alone. This evidence must 

 be taken in connection with the other evidence presented. If the 

 percentage evidence as given is correct, and if it is true that the 

 hybrids are excellent producers, as judged by the number of off- 

 spring produced, then we should expect the egg-production to be 

 greatly increased. The count as given here verifies the expecta- 

 tion and makes the former conclusions more certain. 



The anomalous condition that the fertility of this animal may be 

 relatively low and yet its productivity high, finds its explanation 

 in the facts presented and shows, as before stated, how one may 

 easily be misled in regard to fertility in heredity by using the 

 number of offspring produced as a guide, when not checked up by 

 more accurate means. 



The increased egg-laying capacity on the part of the female may 

 seem strange at first sight, especially when we recall the fact that 

 neither parent possessed it to such a marked degree. But let it 

 be recalled that the hybrid is more virile, as judged by the length 

 of life, than either parent and that the same thing is probably true 

 in regard to their reaction to light. In fact, in every way these 



