38 Action of Normal Haemolysins 



Aves. 



Experiments conducted in vitro by Friedenthal (1900) showed the 

 serum of the fowl to haemolyse the corpuscles of several vertebrates in- 

 cluding those of some birds, namely those of Falco tinnunculus ( Accipitres) 

 and Nyctocorax (Ciconiiformes). The serum of the night heron haemo- 

 lysed the corpuscles of the fowl. The serum of the gull (Larus argen- 

 tatus) haemolysed the corpuscles of the frog. 



Reptilia. 



The toxicity of snake sera for Mammalia is well-marked. Frieden- 

 thal found the intravenous injection of 2 c.c. of the serum of the 

 "Kreuzotter" (presumably Pelias berus Merr.) to be fatal to rabbits 

 of average size. Dr Graham-Smith in trying to produce precipitins in 

 rabbits by injecting the serum of Tropidonafau natrix, found a similar 

 dose to be lethal for guinea-pigs by intraperitoneal injection. Frieden- 

 thal found '5 c.c. of his snake serum to kill frogs when injected into 

 the posterior lymph-sac. He also found the serum of Tropidonotus 

 (" Ringelnatter") to be highly haemolytic. 



The agreement between Aves and Reptilia in possessing a highly 

 toxic serum, may be added to the other points of similarity, as to 

 anatomical structure (skeleton,, urinary apparatus, scales, eggs, etc.) and 

 the microscopic appearances of their blood, which have led systematists 

 to group both classes under Sauropsida. It will be seen, however, that 

 more striking proof has been obtained by means of the precipitins with 

 regard to the relationship between these classes. 



Amphibia. 



Frog Serum possesses haemolytic properties for the corpuscles of 

 the dog, guinea-pig and rabbit, although it acts less rapidly than the 

 serum of Necturus, whose corpuscles it slightly haemolyses (Flexner and 

 Noguchi, 1902). Friedenthal states that the haemolytic power decreases 

 in starved frogs. 



Necturus Serum : The serum of this amphibian quickly haemolyses 

 the corpuscles of the dog, guinea-pig, and rabbit, but slightly affecting 

 those of the frog (Flexner and Noguchi). 



