TRICHINA SPIRALIS. 341 



that any cyst of this kind may have been subsequently broken in 

 some way, either of itself or by mechanical causes, so that the 

 ready-formed worm may have wandered iuto the vicinity of a 

 capsule, and there again inclosed itself and become encysted 

 by the organism. It appears to me as though we must 

 suppose, that these wormless cysts have previously inclosed 

 a further developed Trichina, and that a complete solution 

 of the worm must have taken place. The chemical possi- 

 bility cannot be denied, a priori, and I only regret that the 

 material for investigation was not within my reach, and, from my 

 scientifically isolated position, never can become so. The histo- 

 logical nature of the cyst, no less than the analogy with the 

 Cesloidea, indicate that in the cysts of Trichina we have to do 

 with structures which are analogous to the serous cavities. We 

 may therefore, on the one hand, assume that the fluid surrounding 

 the Trichina is furnished by the serous enveloping cyst as the 

 destined nutritive material for the Trichina, and, on the other 

 hand, that this serous product is subject to the same changes and 

 transformations as other serous products. As we here see a fatty 

 calcareous metamorphosis prevail, we meet in others, for example, 

 with a metamorphosis of the serous contents into thickish, hone}'- 

 yellow (Meliceris-like) , or sizy masses. Now, as we know by 

 experience, that in the fatty calcareous metamorphosis the out- 

 lines of the worm are preserved, and its rudiments remain in the 

 position occupied by it during life, it becomes a question whether 

 the sizy or Meliceris -like transformation of the serous contents 

 (to which transformation the circumstance that the fluid of worm- 

 less cysts of Trichina appeared to be thickened, seems to point), 

 may not perhaps be capable of dissolving the chitinous skin of 

 the Trichina. Had an ovarian or other cyst with size or meliceris- 

 like contents, been at my disposal, I should have taken the 

 chitinous skin of some freshly killed nematode worm, and left the 

 two in contact for a time, at the temperature of the human body, 

 to see whether the skin of the nematode did or did not dissolve 

 in the fluid. As I did not possess this, I must leave the experi- 

 ment to others. As regards the worm itself, we find, as has 

 already been observed, en passant, sometimes two or three, but 

 generally only one specimen of the worm in a cyst. What 

 Luschka and others say of the tenacity of life in the Trichina 

 I can only confirm. Although I could not observe that the 

 Trichina could even support a freezing temperature, still I dis- 



