22 The Cytotoxins of Blood Serum 



to produce anti-haemolysin in guinea-pigs treated with normal rabbit serum which 

 bad been heated. Ehrlich and Morgenroth (in. 1900) obtained anti-isolysin by 

 injecting isolysin (see later) into a goat, noting that there were individual differ- 

 ences in the action of both isolysin and anti-isolysin depending upon the animal 

 from which they were derived. 



Wassermann (1901, Zeitschr. f. Hyg., Bd 37) injected washed rabbit leucocytes 

 into guinea-pigs, obtaining weak but evident " anti-complement " to the complements 

 of rabbit serum, the haemolysis of goat blood by rabbit serum being prevented. 

 Donath and Landsteiuer (25, vn. 1901) obtained a similar result in rabbits by 

 injecting dog leucocytes, crushed lymph-glands, red blood corpuscles and milk 

 severally, but they do not conclude that the autisera obtained in these different 

 ways are identical in character. 



Muller (24, vi. 1901) finds that a number of normal sera possess anti-haemolytic 

 properties, several for instance protected rabbit's corpuscles against duckhaemolysin. 

 This action appears to be due to anti -complement. When he treated (12, vm. 1902) 

 animals with such anti-haemolytic sera, these being inactivated, their serum acquired 

 the property of haemolysiug the corpuscles of the animal which possessed the anti- 

 haemolytic serum. 



Besredka (25, x. 1901) also claims to have observed the existence of anti- 

 haemolysins in the normal sera of man, rabbit, guinea-pig, fowl, and goose. He 

 considers that they represent anti-auto-cytotoxins, whose formation is brought about 

 by the constantly occurring death of certain cells in the body (red blood corpuscles 

 for example), the assimilation of these cells bringing about the formation of this 

 antibody. This view receives support from what has been observed with regard to 

 isolysins in disease. The presence of anti-haemolysin is to be considered as evidence 

 of a reaction on the part of the body, its object being to combat the continual 

 destruction of bodily cells, although at the same time haemolysins are produced. 

 We know that fresh rabbit serum, for instance, haemolyses guinea-pig corpuscles. 

 When heated to 55 C. it ceases to be haemolytic, whereas this heated serum when 

 added to fresh rabbit serum in certain proportions will prevent its exerting a 

 haemolytic action on guinea-pig corpuscles. This does not happen when the heated 

 sera of other animals (man, ox, fowl, goose, etc.) are added instead of rabbit serum. 

 There would therefore appear to be evidence as to the existence of both anti- 

 haemolysin and haetnolysin in the one serum. 



The action of normal haemolysin is not confined to red blood corpuscles. For 

 instance, Delezenne (x. 1900) found that it affected other cells of the same animal 

 as well, to a greater or less extent. Haemolysins act both on the red blood corpuscles 

 and leucocytes, as can be seen in experiments conducted in vitro. To see the 

 effects on other cells the experiments must be conducted to a large extent in 

 corpora Taking eel serum as a type of a haemolytic serum, we find that it is 

 destructive to red blood corpuscles (Mosso, Camus and Gley, Kossel, etc.), to 

 leucocytes (Delezenne, 1898), nerve cells (Kossel and Westphal), renal epithelium 

 (Pettit, 1898). The effects on the nervous system were already observed by Mosso 

 (1888) and Delezenne (x. 1900, p. 693), the latter finding eel serum 200 times as toxic 

 when introduced into the nerve centres as when administered subcutaneously to 

 the same animal. 



Metchnikoff (x. 1899, p. 762) produced " leucotoxins " by injecting an emulsion 



