400 C. H. DANFORTH 



occasions, was lost. With only one hen left, the experiment 

 was discontinued after the morning treatment of that day. 

 Eggs were saved till June 12, the last four being laid by the 

 sole survivor, no. 21. 



Of the six hens originally intended for this work one (no. 

 25) died February 20 at the beginning of the control experi- 

 ment and four others were lost as a result of alcohol treatment. 

 While an adequate number of eggs had been secured for C, 

 there were, owing to these accidents, only thirty-nine available 

 for A (table 2). These were all incubated and yielded enough 

 data to justify the inclusion of this, the least satisfactory of 

 the four experiments. 



RESULTS OF THE EXPERIMENTS 



In the fourth column of table 2 is shown the number of eggs 

 incubated in each subdivision of the experiments. In the fol- 

 lowing columns the results from these eggs are indicated. Num- 

 bers in the fifth column, headed 'non-fertile,' refer to eggs in 

 which no development whatever took place. At the end of 

 three weeks of incubation such eggs were clear and full with a 

 firm yolk; indeed on being broken they presented a more 

 attractive appearance than the average 'store' egg. Only 

 such eggs were counted as non-fertile, except in the case of 

 1-C where the data were originally secured for another pur- 

 pose. Here, in a column headed 'infertile or dying during the 

 first few hours,' were entered data that did not differentiate 

 betweeen early death and actual infertility. The other figures 

 in this column, those for 1-A and for 2, 3, and 4, are believed 

 to be strictly accurate. 



The sixth column indicating embryos killed needs a word 

 of explanation. The capacity of the incubators was not at all 

 times adequate to care for the available eggs. In consequence, 

 since the necessary data can be secured as readily from a fifteen- 

 day embryo as 'from a hatched chick, many eggs were opened 

 between the fifteenth and twenty-first days. A few additional 

 embryos were taken in earlier stages. 



