340 ANIMAL PARASITES. 



times, in cysts with worms which had not long been dead and 

 destroyed, it showed traces of organic retrogression and decompo- 

 sition. Luschka observed in them either the well-known molecular 

 granulations or larger corpuscles, measuring on an average 

 - 008 mill., partly round, partly elliptical, perfectly translucent, 

 and homogeneous, or but rarely delicately granulated, sometimes 

 isolated, sometimes deposited in groups, united by fine molecular 

 corpuscles (fat), not converted into polygonal forms by mutual 

 pressure, quickly soluble in caustic potash, but unalterable by 

 acetic acid, and with a distinct nucleolus measuring 0.00013 mill. 

 In cysts with worms which had long been dead, or in those which 

 contained no worms, these corpuscles were entirely wanting. 

 The wormless cysts are rare, according to Luschka. Amongst 

 several hundreds, scarcely ten occur ; and I do not at all remember 

 having found any such. According to Luschka, they contain a 

 clear, thickish fluid, with small formative elements, or only a few 

 elementary granules, but they exhibited two distinct layers, whence 

 he assumes that the Trichina must have perished by arrest of 

 development in its earliest period, and therefore soon after the for- 

 mation of the inner membrane, but that the cyst itself cannot 

 become empty by the death of a fully-developed worm within it, 

 because the remains of the dead worm might be plainly discovered 

 in other cysts. I cannot entirely agree with this opinion of that 

 frequently mentioned and highly esteemed savant, because I do 

 not find it stated by him that the wormless cysts were at the 

 same time the smallest, scarcely recognisable or measurable cysts. 

 For, if we suppose in general, that the inner layer of the cyst is 

 a product of the worm, and that its formation is commenced at 

 once by the worm in its earliest period, and almost simultaneously 

 with the moment of encystation, which is also my opinion, and 

 which we have seen to be the case, according to Meissner, 

 amongst the Gordii, we must also further admit that the new 

 formation of the inner layer ceases with the death of the worm, 

 and that therefore, if the worm have died in its earliest youth, as 

 Luschka thinks, the inner layer must also have stood still in its 

 growth. This last circumstance must, then, necessarily lead to 

 the result that the cysts either remained quite small, or that, if 

 the outer layer increased in size, and the inner could no longer 

 increase with it, the latter would adhere in pieces to the inner wall 

 of the larger cyst. Of neither of these occurrences do we find 

 any mention by Luschka, and we cannot consequently suppose 



