119 



not mere varieties of one species produced by difference of locality. 

 They are all three found in the brain, for instance. 



As to the genus Acephalocystis, there is good reason for believing, 

 that all genuine specimens of it are Erhinococcus-cysts which have 

 either not developed heads, or in which they have been overlooked. 



The converse of the anatomical evidence as to the identity of 

 Echinococcus with a modified Tcenia, has just been supplied by some 

 very beautiful researches of Von Siebold's, published in the Annales 

 des Sciences for 1 8.02 (or Annals of Natural History, December 18.02). 

 Von Siebold gave to young puppies spoonfuls of Echhiococcus-cyatB 

 in milk. Upon opening them after a short time, he found innume- 

 rable TcBuicB attached all over the surface of the intestine. The cysts 

 had been digested, but the living Echinococci had resisted the action 

 of the stomach, and, freed from their imprisonment, had begun to 

 develope joints. Growth had not gone on sufficiently to enable the 

 learned Professor of Breslau to determine the species. He promises, 

 however, a continuation of his researches ; and it is to be hoped that 

 we may soon have a complete clearing up of the difficulties with which 

 helminthologists have so long been puzzled, from his able pen*. 



III. The literature of Echinococcus exhibits a singular instance 

 of the manner in which naturalists delay their own progress, by not 

 attending to what has been done by their predecessors. Goeze wrote 

 in 1782, and effectually demonstrated the cestoid relations oi the Echi- 

 nococci, as may be seen by the following extracts from his beautiful 

 work (Versuch einer Naturgeschichte der Eingeweidewiirmer) ; nay, 

 before his time, Pallas had on very good grounds conjectured the 

 same thing, and yet half a century afterwards we find this all for- 

 gotten, and speculation rife as to the nature of the Echinococci. 



Goeze thus describes the^cAiwococcM»-vesicles(op.c. p. 258 etseq.): 



" C. The small social granular Bladder tape-worm (Blasen-band- 

 wurm) : Tcenia visceralis socialis yranulosa. 



" This is as it were an intermediate form between the great globular 

 Bladder tape-worm {Cysticercus), and the many-headed worm found 

 in the brain of staggering Sheep. 



" I had already read what Pallas supposes on this subject in the 

 •Neue Nordische Beytriige,' i. p. 85, when, by a lucky discovery, I 

 made the whole matter out. 



"Upon the 1st of Nov. 1/81, I met with an excessively distorted 

 Sheep's liver, which was so beset and penetrated by large and small 

 watery vesicles, — the former as large as hens'-eggs, the latter as 

 hazel-nuts, — that, externally, one could discern hardly anything of 

 the substance of the liver. 



" The animal itself was almost perfectly healthy. In its total size, 

 this monstrous liver was about equal in breadth to the two hands ; 

 and its length was about half an ell : the weight however was four 

 pounds. I was obliged to divide it into two portions in order to be 

 able to get it into a large jar (3 inches, glass) with spirit. When I 



* A full account of Siebold's investigations has, in fact, appeared in Siebold 

 and Kolliker's ' Zeitschrift ' for 1853, unfkr the title, " Ueber die Verwandlung 

 der Echinococciis-bnit in Tanien." — T. II. April 1851. 



