50 LECTURE IV. 



however, is most probably only a seminal vesicle, and not the testis. 

 The vas deferens is continued from the vesicle with slight undu- 

 lations, to the middle of the segment, where it bends upon itself at a 

 right angle, and terminates at the generative pore {fig. 22, «), from 

 which the lemniscus, or rudimental penis, projects. The ova may be 

 fecundated by intromission of the lemniscus into the vulva before they 

 escape. 



The segments containing the mature ova are most commonly 

 detached and separately expelled. Tlie development and metamor- 

 phoses of the embryo Taeniae have not yet been completely traced 

 out. In the Tenia serrata and other species in which the embryo 

 has been observed, the head is first formed and is provided with six 

 hooks ; it rotates in the ovum, doubtless by means of superficial vi- 

 bratile cilia. 



For a knowledge of the minute anatomy of the Bothriocephalus latus 

 {figs. 23, and 25), we are indebted to the admirable skill and patience of 

 Professor Eschricht, of Copenhagen, whose work* on the subject has re- 

 ceived the prize of the Academy of Sciences, at Berlin. His observa- 

 tions were made on a specimen of the worm, which, after various re- 

 medies, was dislodged from one of his patients. 



In Denmark, as in Holland, the Tcenia solium is the common tape • 

 Avorm; but the case in question occurred in a female aged twenty-three, 

 born at St. Petersburg, of Russian parents ; who had spent almost all 

 her childhood and youth at Copenhagen, with, however, occasional so- 

 journs of three or four months' duration, in Russia. The usual symp- 

 toms of tapeworm, with occasional ejection of fragments, occurred in 

 1834. She had also distorted spine and other indications of a weakly 

 constitution. Thrice, in that year, oil of turpentine with castor oil, 

 and once some strong drastic pills and pomegranate rind, were adminis- 

 tered ; and, with the exception of the last medicine which produced 

 no efi'ect, each time from twelve to twenty feet of the worm were ex- 

 pelled, but without the head. In the spring of 1835, she was induced 

 to try a remedy called " Schmidt's cure," which consists of strong 

 coffee, and salt herring ; and it was followed by the expulsion of a 

 piece of the worm measuring ten yards, still without the head. She 

 then paid a visit to Petersburg, and there parted with four or five 

 pieces of the tapeworm measuring from two to four feet in length. 

 She returned to Copenhagen in the winter of 1835, still suffering from 

 her pertinacious parasite. Castor oil and turpentine were again ad- 

 ministered on the 3d of December, and procured the ejection of two 

 pieces of the tapeworm, measuring together twelve feet in length, but 



* Anatomisch. Physiologische Untersucluiiigen iiber die Bothryocephalen. 4to. 

 18 40. 



