138 CHEMISTRY OF THE ANIMAL PARASITES 



found to have in their blood antibodies giving precipitin ^^ and com- 

 plement fixation -" reactions with extracts of echiuococcus, and some- 

 times with other taenia.^" The antigen of the echinococcus is be- 

 lieved by some to be a lipoid ;^^ in the case of Taenia sagitiata, at 

 least, it seems to be associated with the lecithin (Meyer ^"). Graetz,^^ 

 however, states that the protein of the hydatid cyst is derived from 

 the host, and that it is therefore incapable of causing anaphylaxis in 

 that host, but it may undergo alterations in the cyst so that it is 

 toxic after the order of anaphylatoxins {q. v.). The complement fixa- 

 tion reaction with echiuococcus fluid has been found quite reliable in 

 the clinic, 93 per cent, of positive reactions having been obtained in 

 500 cases collected by Zapelloni,^-'' while controls were always negative. 



The fluid of the echinococcus cysts has generally a specific gravity 

 of 1005-1015, and contains 1.4-2 per cent, of solids. Most abundant 

 are sodium chloride, about 0.8 per cent., and sugar, 0.25 per cent., 

 the latter presumably coming from the glycogen contained in the 

 wall. Cholesterol is often abundant, while inosite, creatin, and suc- 

 cinic acid are often found. Clerc has found traces of lipase, but 

 other enzymes seem to be absent or in very small amounts. Proteins 

 are present only in traces, unless inflammation has occurred. Schil- 

 ling ^^ found the molecular concentration of the cyst fluid to be quite 

 the same as that of the patient's blood. The fluid is said not to be 

 toxic to laboratory animals.^* 



The cyst wall consists of a hyaline substance which seems to stand 

 between the chitin and the proteins, and probably consists of a mix- 

 ture of both. Because of the chitin it yields about 50 per cent, of 

 a reducing, sugar-like body when boiled with acid. Glycogen is also 

 usually present, but it is limited to the germinating membrane.^^ 



Other cestodes, when in the cystic form, contain fluids which are 

 more or less toxic. Thus Moursou and Schlagdenhauffen ^^ found a 

 "leucoma'in'' in the Cysticercus tenuicollis, the larva of Taenia mar- 

 ginata, which causes urticaria and other toxic symptoms when in- 

 jected into animals. The fluids of Cysticercus pisiformis (the com- 

 mon cestode of rabbits) have been found toxic for frogs, and Vaulle- 

 geard ^^ has determined the presence of an "alkaloid" and a ''fer- 

 ment toxin" in this fluid. The fluids of the cysts of Caenurus cere- 

 hralis, Coenurus serialis, and Echinococcus polymorphiis have all been 



28 Welch, et al., Lancet, 1009, Apr. 17. 



29Kreuter, Miinoh. mcd. Woch., 1900 (50), 1828; Weinberg, Ann. Inst. Pasteur 

 1909 (2.3), 472. 



3o\Ii.v(.r, Berl. klin. Woch., 1910 (47). 1310; Zeit. Inmiunitjit., 1910 (7). 732. 



31 Israel, Zeit. ITyg., 1910 (00), 487; Meyer, Zeit. Immunitiit.. 1911 (9), 530. 



32 Zeit. Iiniiumiliit., 19)2 (15), GO: general review. 

 32aPoliclinico, Surg., 1915 (22), Nos. 0-11. 



33 Cent. inn. Med., 1904 (25), 833. 



340raet/„ Cent. f. Hakt., 1910 (55), 234; ZiMt. IniimiMitiit .. 1912 (15), 00. 

 85 Brault and Loeper, Jour. Phys. et Patli. g^n., 1904 (0), 295. 

 soCompt. Rend. Soc. Riol., 1882 (95), 791. 

 37 Bull. Soc. linneenne de Normandie, 1901 (4), 84. 



