132 CHEMISTRY OF THE AMMAL PARASITES 



tion reaction with echinococcus fluid has been found quite rehable in 

 the cHnic, 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 enzj'^mes 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 chitin and protein, and probably consists of a mixture of 

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

 sugar-like body when boiled with acid. Glj'cogen 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 SchlagdenhaufTen*- found a 

 "leucoma'in" in the Cy.sticercus tenuicoUis, the larva of Taenia 'mar- 

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

 jected into animals (thus resembling histamine). The fluids of 

 Cysticercus pisifonnis (the common cestode of rabbits) have been 

 found toxic for frogs, and Vaullegeard*^ has determined the presence 

 of an "alkaloid" and a "ferment toxin" in this fluid. The fluids of 

 the cysts of Ccenurus cerebralis, Ccenurus serialis, and Echinococcus 

 polymorphus have all been found toxic, and it is probable that this is a 

 general rule with the cestodes,'''' but human forms other than the echi- 

 nococcus seem not to have been investigated;'''' according to Jnmmes 

 and Mandoul, extracts of taenia are bactericidal.^" 



Dibothriocephalus latus ficqucntly causes anemia, which has been 

 attributed to a poison liJK'rated by the parasite when it undergoes 

 disintegration, and possibly as a secretion of the living worm.'*^ All 

 the intestinal cestodes iire equipped with a well-developed excretory 

 apparatus, and it is easy to imagine that their excretory prochicts 

 may be toxic to tlic animal into whose intestine they ai'e exereteil. 



3» Policlinicu, Suim;., liKf) (22j, \us. ti 11. 



3»Cent. inn. iMid., 1904 (2.'3), HXi. 



■"•Uraetz. Cent. f. IJukt., 1910 (.Wj, 2:U; Zi-it. Iniiiuinitat. 1912 (15), 60. 



^' Hrault und Loupcr, .K)ur. I'livs. et. Tatli. m''n., H'Ol (ti), 295. 



^■-Coinpt. Hcnd. S(.c. Bio!,, I8S2 (95), 791. 



■••' Bull. S(K'. liniu'cniic (li? Nurinaiulie, 1901 (l), SI. 



" HhuK-liaid., Iin- ril.-' 



■"• Scniaiai- iiu'd., 1905 (25j, .55. 



^« See alo .Joycu.x, .\rcli. d. I'aiasitol., 1907 (ID, 409. 



*'' Litt'ia lire l)\- Kl;iiu-liai(l, lor <•//.-■' 



