Graham-Sniith 351 



This antisn-iuu was a powerful one, bub was very slightly opalescent. 

 As shown in the above table, however, it was entirely eonfined to the 

 Reptilia in its reactions. The niaxinnnn reactions occui-red amongst 

 tlu' Lacertilia, though fairly well-niark(>(l clouding and pi-ecipita were 

 obtained with the Ophidia as well as the Chelonia and Crocodilia. It 

 is unfortunate that both the Lacertilian antisera were somewhat un- 

 satisfactory, the first being very weak, and the second slightly opalescent, 

 rendering the determination of slight reactions difficult. In the latter 

 case all very slight cloudings have been disregarded, and a clouding 

 usually described by the sign * has here been marked as * i. The 

 larger reactions were however well marked and unmistakeable. 



D. Auti-Ophidi(tn Sera. 



(I. Qualitative Tests. 



(1) Tests with Anti-Snake Serum. 



This antiserum was obtained by the intraperitoneal injection into a 

 Rabbit of Snake serum (Tropidonotus natri.r). The serum had been 

 previously heated to 55'" C. in order to destroy its toxic properties. 



Percentage 

 of positive 

 X + + reactions 



10 



1 . 100 





 



1.3 



.50 



40 



4 11 40 















This was a moderately powerful antiserum, producing its maximum 

 effects amongst the Ophidia. The few reactions obtained wnth Chelonian, 

 Crocodilian and Lacertilian bloods were all feeble. One bird's egg- 

 albumin (Moorhen) gave a small reaction, but a well-marked clouding 

 follow^ed b}^ a deposit was obtained with a dilution of snake's egg- 

 albumin, and a smaller clouding with tortoise egg-albumin. 



