SECTION VI II. 



BLOOD-RELATIONSHIP AMONGST THE LOWER VERTE- 

 BRATA AND ARTHROPODA, ETC., AS INDICATED 

 BY 2,500 TESTS WITH PRECIPITATING ANTISERA. 



BY G. S. GRAHAM-SMITH, M.A., M.B., D.P.H. (CAMB.). 



IN the foregoing pages Nuttall has described in detail the various 

 methods of collecting and preserving sera, and of preparing antisera, 

 together with the precautions which have to be adopted in testing, 

 both by the qualitative and quantitative methods. 



These experiments were conducted by the methods he has described, 

 and it is therefore unnecessary again to describe them. 



On reference to Nuttall's tables it will be seen that his work was 

 principally carried out on Mammalian and Avian sera, though Reptilian, 

 Amphibian, Fish, and Crustacean sera as well as a few Egg-albumins 

 were tested. In order to render these experiments more complete it 

 was thought desirable to further study the relationships indicated by 

 this test amongst the latter groups of animals, and Egg-albumins. For 

 this purpose Dr Nuttall kindly placed at my disposal all his specimens 

 of blood of the Reptilia, Amphibia, Pisces, and Crustacea, and these 

 together with a few others have been tested with antisera derived from 

 animals of their own classes. 



Methods. 



Production of Antisera. 



In these experiments some of the antisera were prepared by the 

 intraperitoneal method, and some by the intravenous, but the injection 

 of much smaller quantities than those usually employed was found to 

 suffice (see table, p. 337). Continental workers have used quantities 



