598 GEOFFREY SiVnTH. 



3. The Effect on the Body-weight, General Health, etc. 



The series of weiglits of injected and non-injected hens 

 sliows that the injections do not have any constant effect on 

 the weight of the body, even in the young animals used in 

 Experiment 3. With regard to effect on general health it is 

 true that one of the injected birds (No. 1) became unwell 

 after the injections, appearing anaemic and with reduced 

 temperature, and another (Xo. 8) died soon after the injec- 

 tions ceased, but seven of the injected birds showed no 

 symptoms of any discomfort, hiid well, and maintained their 

 weight. It is therefore very probable that the two ill-haps 

 Avere either purely coincidents or else due to accidental 

 infection, and not to any poisonous action of the extract 

 injected. Dr. AValker gives as the result of his injections 

 that the hens became quarrelsome and attacked cocks that 

 were put in with them. It niay be mentioned that no such 

 characteristics were developed by any out of my nine 

 injected birds. 



4. The Effect on the Fertility of the Eggs. 



Since the extract contains a large quantity of ripe nnd 

 partially ripe spermatozoa, it was interesting to inquire if the 

 injected hens might be rendered immune against the cock's 

 spermatozoa, and if the presence of an immune substance 

 in the body-fluids might render fertilisation impossible 

 or abnormal. In order to test this, eggs laid by injected 

 hens during the period of their injection were incubated to 

 the third or fourth day together with eggs from control 

 birds and the result noted. As will be seen from the schedule, 

 four of the injected birds laid eggs during the full period of 

 injection, and these eggs were in all cases fertile and 

 normal in development. From some of these eggs healthy 

 young were actually raised which showed no abnormalities. 

 We may conclude, therefore, that the injection of the extract 

 has no influence either on eo-o--lavin"- or on the fertilisation 



