ii2 SCIENCE PROGRESS 



must remain intact (Hausmann, Abderhalden and Le Count). 

 The antagonistic action of lecithin and cholesterin has been 

 strikingly demonstrated by Pascucci in his experiments with 

 artificial blood corpuscles. (Glass cells containing haemoglobin 

 solution and covered with a membrane impregnated with 

 lecithin, cholesterin, etc., were suspended in the toxin solution, 

 and the diffusion of the pigment taken as an index of haemolysis.) 

 The poison of scorpions and bees behaves in the same way 

 towards lecithin (Morgenroth and Carpi). 



It is still too early to form a definite opinion about the 

 chemical nature of these Toxolecithides, as they have been called. 

 It has been suggested that the action of toxins is partly a 

 lipolytic one. In this connection it is interesting to note that 

 oleic acid and oleates (soaps) play a role in haemolysis and 

 bacteriolysis (Liebermann, Noguchi). The analytical figures 

 furnished by cobra lecithide, which agree with the formula of 

 lecithin minus a fatty acid radicle, would seem to be in accord 

 with a lipolytic action of cobra venom. 



Lipoids. — The chemical investigations on the isolation, pro- 

 perties and constitution of the lipoids have received a fresh 

 stimulus through the above observations, after having attracted 

 relatively little attention during the latter part of the last century. 

 This neglect was no doubt partly due to the harmful influence 

 of the "Protagon" idea, introduced by Liebreich in 1865. 

 According to this theory all the constituents of nervous tissue 

 (known at this time as phosphorised fats, lecithin, cerebrin, etc.) 

 do not exist preformed, but are derived from the decomposition 

 of the one and only mother substance, which was therefore 

 called " Protagon." This product was supposed to possess a 

 definite chemical composition, but has now been finally proved 

 to be a mechanical mixture (Gies, Rosenheim and Tebb). The 

 general acceptance of the " Protagon " idea until quite recently, 

 notwithstanding the strenuous opposition of Thudichum, has 

 retarded considerably the progress of our knowledge not only 

 of the substances constituting the mixture " Protagon," but of 

 the lipoids generally. Thudichum's observations are being 

 confirmed by modern workers in this field, and the classification 

 proposed by him is now generally accepted. It is not only 

 applicable to the lipoids of the brain, but also to those contained 

 in cells generally. 1 A short discussion of the substances be- 

 1 See I. Bang, " Biochemie der Zell-Lipoide," Ergebn. d. Phys. 1907. 



