418 ANIMAL PARASITES. 



find in them accidental favorable circumstances for thriving, 

 maintain and increase them, and whether these catarrhs may 

 not still persist independently after the removal of all the worms, 

 in spite of all subsequent treatment, supposed to strengthen the 

 mucous membrane. 



Lastly, many of the older authors, and, very recently, 

 Zimmermann, have attributed to the worms a prognostic and 

 generally unfavorable import in certain febrile disorders of the 

 intestine, especially in typhus. Zimmermann never saw the 

 worms pass off in typhus before the seventh day. The passage 

 of the worm only furnishes a doubtful, indirect, prognostic 

 indication. When it takes place in the latter period of typhus, 

 and after the patient has fasted long, it indicates simply that the 

 Ascarides which live upon the chyme in the human intestine are 

 hungry and pass off because they find nothing. The proof of 

 this is the state of fulness or emptiness of the intestines of the 

 worm. If it occurs in the earlv davs of the tvphus and with 

 general symptoms of serious illness and numerous diarrhceal 

 stools, it indicates that the attack of typhus is a severe one, 

 that the typhous ulcers may extend high up in the intestine, so 

 that the acrid secretions reach, irritate, and even expel the 

 Ascarides which live higher up. That there must be a con- 

 dition of the intestinal canal, which favours the thriving of the 

 worms, is clear. Whether, as is commonly supposed, this con- 

 sists in an accumulation of intestinal mucus is by no means 

 ascertained. Hence the after treatment is for the present a 

 purely empirical one. 



Therapeutics. — 1. Prophylaxis. — The first thing to be done by 

 the surgeon in practice consists in destroying the eggs of the 

 Ascarides wherever he meets with them, and expelling every 

 female that he can get at. It was H. E. Richter's merit that he 

 first ascertained that the eggs remain uninjured in sewage, &c. 

 Recently, Barry, Bischoff, and others, have proved that the pro- 

 cess of segmentation of the eggs of Nematoida continues even in 

 very concentrated alkalies or salts. According to the experiments 

 of Verloren and Richter, already described, the eggs of Ascarides 

 only attain their full maturity when free in nature (in water), 

 and only undergo the process of segmentation in this situation. 

 In the various species of Ascarides, the time necessary for this 

 purpose may be different. For whilst, according to Verloren, this 

 is completed in one species of Ascaris within a few weeks, the 



