GralKwi-Snuth 339 



though they arc probaljly only of vahu' wherci the antisei-uin reacts in this 

 way with several lueinbcrs of a group. In every table the number of 

 reactions of each kind has been given, and the results of tests with each 

 antiserum either including, oj- omitting, these reactions of doubtful value 

 can be seen. 



Several instances occurred in which though no clouding appeared in 

 two hours yet a procipitum was present after 24 hours. The majority 

 of these are probably true reactions, and are inserted in the tables at the 

 end, but are not included in the summarised results of the individual 

 antisera. 



In Quantitative experiments the method devised by Nuttall (5. V[. '02) 

 and described elsewhere (p. 315) was employed. 



In all cases dilutions of the strength of 1 : 21 in '670 s-'ilt solution 

 of Egg-albumins or sera to be tested were used. 



In similar observations on Human and other sera it had been found 

 that Avith every precaution probably a margin of 10'Y„ must be allowed 

 for experimental error (p. 318). 



In the following table the antisera are placed in order according to 

 their strength, as shown by the amoimt of precipitum produced by each 

 with its homologous serum when tested by the quantitative method. 



Auti-Limulus (I) -0980 c.c. Anti-Fowl's-egg (I) -Olof) c.c. 



,, (II) -OoOO ,, An ti- Snake serum -0159 ,, 



Anti-Tortoise (T. ibera) -0894 ,, Anti-Crab serum -0140 „ 



Anti-Duck-egg -0884 „ Anti-Fowl's egg (II) -0122 ,, 



Anti-Turtle -0300 „ Anti-Crane's egg -0073 „ 



Anti-Emu-egg -0281 ,, Anti-Uromastix trace 



Anti-Tortoise (T. vicina) ...-0234 ,, Anti-Python ,, 



The anti-ammocoetes, and anti-snake's-egg sera produced well-marked 

 precipita, but the strengths of the dilutions tested were unknown. These, 

 however, were certainly not j\s strong as 1 : 21. 



Anti-lizard (Varanus griseus) was a powerful antiserum, but no 

 quantitative tests were made, as the quantity of it was very limited. 



Materials used in these experiments. 



All the ogg-albumins were kept in a fluid condition in 1 : 21 dilution 

 with '6 Yo 8alt solution. Fluid sera, reptilian, amphibian, and crustacean, 

 were similarly preserved. In many cases a few drops of chloroform were 

 added to prevent putrefaction. Before testing, small quantities of the 

 dilutions were allowed to stand in watch-glasses in order to allow the 



22—2 



