176 OXYURIS-LARV^ HATCHED IN THE HUMAN STOMACH, 



exactly similar constriction in the intestine of the larvse of 

 Rhabdonema nigro-venosum. One is reminded of the 

 peculiar formation of the posterior part of the intestine in 

 D o r y 1 a i m u s, without however receiving thereby any 

 elucidation of the present structure. What I regard as the tru© 

 rectum is narrow and has a length not exceeding that of the anal 

 diameter. There seem to be several one-celled glands around the 

 rectum. Where they empty I cannot say. In the larvse of 

 Oxyuris obvelata, the x y u r i s of I'ats and mice, I have 

 seen corresponding one-celled glands and am certain that they 

 empty by long narrow ducts iiito the rectiun at its middle. 



Muscular System. 



Observations on the muscles were unsatisfactory. The muscle- 

 cells were distinctly visible and the system seemed to be that of the 

 Nematodes called by Schneider* P o 1 y ni y a r i e r. The adult 

 Oxyuris belongs to his M e r o m y a r i e r. 



Rejiroductive Organs. 

 The cells destined to give rise to the reproductive organs lie 

 in the ventral part of the body cavity somewhat behind the 

 oesophagus, (s, Fig. 2.) 



Jugular Cells. 



Under this non-committing name I call attention to some cell- 

 masses in the neck of the larva. I think there are three such 

 masses. They may have some connection with the nervous 

 system, (j, Fig. 2.) 



Nervous System. 



The nerve-ring is not easily discovered. From a large number 

 of observations, however, I have been enabled to determine its 

 position, as will be seen by the figure and the formula. It 

 encircles the cesophagns considerably in front of the median bulb, 

 and, like the nerve-ring in the adult worm, is not in the least 



oblique. (Fig. 2, n.) 



* " Monographic der Nematoden," &c. 



