134 CHEMISTRY OF THE ANIMAL PARASITES 



several other taenia were obtained by Langer,^* but complement fixation reactions 

 may be given/* 



Picou and Ramond^" state that tirnia extracts undergo putrefaction very 

 slowly, and attribute this to a bactericidal property, which was observed with 

 several forms of ttmia by AUesandrini. Weinland^' has found that many intes- 

 tinal parasites exhibit antitnjplic properties, ^^ but in a study of the histological 

 changes of autolysis I observed a t enia in the intestine of a dog undergo more 

 rapid karyolytic changes than did the intestinal epithelium. Dastre and Stessano*' 

 state that extracts of Taenia serrata act upon enterokinase rather than on tryp- 

 sinogen. 



NEMATODES 



Ascaris. — The toxicity of members of this group has been a matter 

 of dispute, although, as with the Taenia, there have been observed in 

 patients symptoms that ^vere more easily explained as due to chemical 

 substances than as due to mechanical irritation. Miram, while 

 studying Ascaris megaloceyhala, suffered from attacks of sneezing, 

 lachrymation, itching, and swelling of the fingers, v. Linstow suffered 

 from a severe attack of conjunctivitis with chemosis after touching his 

 eye with a finger that had been in contact with one of these worms. 

 Others have had similar experiences, and it has been found that the 

 fluid from these worms is toxic to rabbits. In man it seems to affect 

 especially those who have been sensitized by previous poisoning, some 

 persons being entirely insusceptible. 



An extensive investigation of ascaris from both the chemical and 

 toxicological standpoint has been made by Flury,^* which indicates 

 the source and nature of these toxic substances. Because of the 

 practically anaerobic conditions under which the worms live, Flury 

 believes, the products of their metabolism are charactetized by being 

 incompletely oxidized, and resemble the products of anaerobic bac- 

 teria. Most important of these are volatile aldehj'des and fatty acids, 

 especially valerianic and butyric acids, in less quantities formic, 

 acrylic and propionic acids. The toxicologic action of these volatile 

 substances is of such a character as fully to explain the severe irrita- 

 tion of skin and mucous membranes observed in persons handling 

 these parasites; aldehydes are notoriously inclined to produce con- 

 ditions of hypersensitivenoss, c. r/., formaldehyde. It is quite jiossi- 

 ble that the severe constitutional symptoms observed occasionally in 

 persons infected with ascaris, are produced by these substances or 

 by poisonous substances set free through disintegration of worms 

 which have dietl and renuiined in the ])()wcl. A capillarv poison re- 

 sembling scpsin, poisonous bases acting lik(> atropine and coniine, 



" Munch, mod. Woch., 1905 (.W), 1(H)5. 

 '» Mover, Zoit. Immunit;it., 1<H0 (7), 732. 

 "o Comi)t. Rend. Soc. iiiol., 1S<M) (f)!), 17G. 

 9| Zoit. f. Hiol., 11)02 Ml), 1 and -ir). 



'- Corrcjboratod for 'I'druii /iiuiinnta by Fetterolf (I'niv. of IVnnsvlvania Mod. 

 Bull., 1907 (20), 91). 



«^ Compt. liond. Soc. Hiol., 1903 (55), 130. 



"'Arch. oxp. I'alh. ii. I'li.i, iii., 1<)12 (07), 275 (litonituro). 



