ON THE ANATOMY OF THE ECHINOCOCCUS VETERINORUiM 211 



The cysts had a laminated outer coat ; some contained EcJiinococci 

 and some none, but in other respects they were completely alike. The 

 EcJiinococci exactly resembled the ordinary figures. 



" In a few of the free ones, a trace of a membranous cord, looking 

 as if it had been torn off, appeared at the posterior end of the body ; 

 as if the worms had at an earlier period been fixed." 



MiJller could not make out whether the Ecliinococci were fixed to 

 the interior of the secondary vesicle or not. 



Tschudi, 'Die Blasenwiirmer, 1837,' observed the retrograding 

 yellow Ecliinococci, which he assumes to be returning to the vesicular 

 form. He considers that the " corpuscles" are ova, and that by their 

 development in the interior of one of these retrograded Ecliinococci, 

 the secondary cysts are formed. 



Gluge, ' Annales des Sciences Naturelles, 1837,' describes the 

 ■corpuscles of the Ecliinococci very carefully and minutely. He was 

 the first to notice the peculiar structure of the endocyst. He says, 

 " I have constantly seen in it a kind of arborization very similar to the 

 ■formation in fibrinous exudations during the first stage of inflamma- 

 tion. We see these transparent bodies with slightly irregular contours 

 resembling empty blood vessels and ramifying like them. I do not 

 know whether these are true vessels, I merely draw attention to 

 the fact." 



In the same year (1837) the second edition of Burdach's ' Physio- 

 logic ' appeared. It contains an admirable chapter by Von Siebold, 

 upon the development of the Entozoa. Burdach's work is so little 

 known, and so inaccessible in this country — that I think it worth 

 while to subjoin the whole of what Von Siebold says upon this 

 subject : — 



" In the development of the Ecliinococci also, much has remained 

 obscure. We must in them always distinguish two things ; the parent 

 vesicle, and the proper Ecliinococci &nc\oscii within this. The maternal 

 vesicle is covered internally by an excessively delicate epithelium, in 

 which are contained corpuscles similar, though here generally elon- 

 gated, to those which we have found in the neck of Ccemtrus. In the 

 fluid which the maternal vesicle encloses, we meet with a few Ecliino- 

 cocci, which when they have everted their coronet of hooks and their 

 suckers, allow nothing to be perceived in their interior but a few 

 scattered glassy corpuscles. These Ecliinococci evidently arise from 

 the inner surface of the parent vesicle. My own observations here- 

 upon have been made upon E. Iwminis, E. veterinorum, and a new 

 ■species which, since the number of its suckers varies very much, I will 

 -call E. variabilis. On examining the inner surface of the parent 



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