FURTHER DEVELOPMENT OF KNOWLEDGE 173 



necessarily prove that the thyroid can be looked upon as a source 

 of alexin, and, indeed, Fassin gives experimental results without 

 drawing any very sweeping conclusions. It might well be that the 

 thyroid secretion is simply concerned in stimulating the production 

 of alexin from another source. Marbe 23 has similarly associated 

 the thyroid gland with the production of opsonins, which, when we 

 consider the probable identity of alexin and normal opsonin, may be . 

 taken as a confirmation of Fassin's work. 



Of great interest also are the series of investigations which asso- 

 ciate the liver with the production of alexin. The basis of such 

 investigations is found in the observations made by Morgenroth and 

 Ehrlich 24 that there is a diminished production of complement or 

 alexin in dogs subjected to phosphorus poisoning, with consequent 

 degeneration of the liver. The first investigator to study this ques- 

 tion experimentally was Nolf. 25 Nolf tried to approach it by extir- 

 pating the liver in dogs, and found that his results were unreliable 

 by this method. He then experimented with rabbits and found that 

 when the liver was extirpated in these animals and the vena cava 

 anastomosed with the portal vein (Eck fistula) the animals would 

 survive for three or four hours. This period, though short, was suffi- 

 cient to show definite changes in the blood. Taken just before death 

 it differed from that taken just before the operation in a number of 

 important respects. There was relative incoagulability, there was 

 autohemolysis, and with these there occurred an extreme fall of 

 alexin or complement. Serious objections may be brought against 

 Nolf ? s experiments. In the first place the operation as performed by 

 him results in shock and injury so profound that rapid death ensues, 

 conditions under which not only the complement-producing functions 

 but all functions, secretory and otherwise, are reduced. Miiller 26 ob- 

 jects to Nolf's experiments chiefly for the reason that he did not pre- 

 vent the absorption of toxic substances from the intestine, materials 

 which could now enter the general circulation without any longer be- 

 ing neutralized by the liver functions. Miiller, for this reason, re- 

 peated Nolf's work but, by a complicated technique, temporarily shut 

 off the intestinal circulation in addition to extirpation of the liver. 

 He found, in agreement with Nolf, that exclusion of the liver from 

 the circulation resulted in the prompt diminution of complement or 

 alexin. In all such experiments, however, the very profound shock 

 which necessarily occurs in the animals would seem to us to vitiate 

 the results. Moreover, Liefmann 27 has repeated Miiller's experi- 

 ments without being able to obtain the same results. Not satisfied 



23 Marbe. C. E. de la Soc. Biol., Vols. 64, et seq., 1908-1909. 



24 Morgenroth and Ehrlich. In Ehrlich's "Gesammelte Arb.," etc. 



25 Nolf . Bull, de I'Acad. de Science de Belg. } 1908. 



26 Miiller. Centralbl. f. Bakt., Vol. 57, 1911. 



27 Liefmann. Weichhart's Jahresbericht, Vol. 8, 1912, p. 155. 



