360 DR. T. S. COBBOLD ON SIMONDSIA PA11ADOXA. 



The host was a " boar" suffering from an affection of the skin, a circumstance which led 

 to its being killed and employed for dissection-purposes. Though well fed, it was a poor, 

 lean animal, and, during life, afforded neither sign nor symptom of gastric disorder. 

 Before Professor Simonds detected the parasites, some portions of the stomach had 

 already been removed ; and thus it is concluded that many specimens of the parasite 

 escaped observation. 



The cavities, or cysts, formed in the walls of the stomach by the female parasite are 

 remarkable structures. Each gastric cyst contained a single female worm. The cysts 

 projected both externally, at the peritoneal surface, and internally, causing a bulging of 

 the mucous membrane. 



Professor J. B. Simonds states that there was no evidence of the existence either of 

 congestion or of inflammation in the surrounding tissues. When a cyst was opened, some 

 clear fluid escaped ; nevertheless a small aperture at the mucous surface permitted the 

 head and neck of the female parasite to project into the cavity of the stomach. The 

 cavity of each gastric cyst not merely enclosed the body of the worm, but formed, as if 

 were, a perfect cast of the rosette-like organ. On transverse section, each gastric cysf 

 displays six or seven distinct circular rows of depressions internally (PI. XXXVII. fig. 4). 

 These depressions are regularly arranged, and are themselves made up of smaller cavities, 

 generally from four to six in each of the larger depressions. The ultimate ca:cal ends 

 of the rosette are received into still smaller cup-shaped cavities proceeding from the 

 secondary depressions. The number of these caeca varies considerably, some of the main 

 branches of the, rosette supporting upwards of forty of them. 



The formation of these peculiar gastric cysts can only have been brought about by the 

 gradual development of the enclosed parasite, the gentle and equable pressure of the 

 slowly expanding body of the worm causing so perfect an adaptation of the environment 

 that every part of the thin-walled rosette became protected from injury. It is hardly 

 likely that the ultimate purpose of this cyst is concerned with the mere steadying, 01 

 fixing of the body of the worm during sexual congress. 



The symmetry of form and sculpturing of the cysts thus produced by Simondsia is« 

 almost as perfect as the somewhat similar appearances seen in fossil casts ; and, although 

 their mode of formation must have been essentially different, it is impossible that the 

 analogy should escape notice. Prom the helminthic standpoint, these gastric cysts musl 

 be pronounced unique ; nevertheless, in respect of their mode of formation, something 

 of the same kind may be observed in the cast-like depressions formed by the anchored 

 heads of various species of Taenia and Echinorhynchi. Pentastomes and Gastrophilm 

 larvae also produce depressions of a simple character. 



As regards the anatomy of Simondsia, I have only further to state that the integumem 

 is everywhere striated, except at the surface of the rosette. Only on the tail of th( 

 female worm were there any spines observed. They occur on the ventral surface, at i 

 distance of about -^ of an inch from the tip. The spines, three in number, are placet 

 in a transverse row. They are nearly as broad at the base as they are long, separatelj 

 measuring about 3^ of an inch from base to apex. The body of the male worm afford; 

 an average diameter of -£$ of an inch, the female being one sixth broader ; the tail of th< 



