TRICHINA SPIRALIS. gy 
self with the appearance of the worm as itis found in flesh. To 
this. end if is well to procure a specimen properly mounted as a 
microscopic object. Such specimens may be procured at a very 
trifling cost from almost any dealer in microscopes. The specimen 
should be such that the worms can be distinctly seen in the cyst, so 
that the learner may be able to recognize it without possibility of 
mistake or doubt. Writers on this subject describe several objects 
which may be mistaken for trichinz, but for our purposes they are 
of no consequence whatever. If, after proper preparation, no worms 
can be seen, it does not matter what dark or oval specks we may 
find:* 
Let us suppose, now, that we have a suitable microscope at our 
command, and that we wish to examine a piece of flesh for the pur- 
pose of determining if trichinz be present. If we have the whole 
animal at our command, the parts that should be selected as being 
the most likely to harbor this parasite are the diaphragm, the tender- 
loin, and the muscles about the head and throat. In a ham the 
most likely place is that part at which the muscle ends in the 
tendon. From any of these parts take a very thin slice, lengthwise 
of the fibre, with a very sharp knife, or, which is better still, a 
razor. Others use a pair of scissors, curved on the flat, as it is called. 
By means of such scissors, it is easy for the most inexperienced 
person to cut a piece which shall taper off to a very thin edge. 
Where the operator has plenty of time at command, this thin section 
*This must be taken, however, as applying only to cases in which the 
number of such objects is comparatively small. M. Megnin, in a paper 
read before the Society de Biologie, points out that many minute en- 
eysted worms are met with which are not trichine, although so closely 
resembling them as to have deceived many observers. The supposed 
discovery of trichine in the rootlets of beet-root, proved by Virchow and 
Kuhn to be a mistake, isa striking instance of this sort. Langenbeck 
deseribed trichine in the intestines of earth worms, but Kuhn showed 
that the parasite is quite distinct from the trichina spiralis. Merlan and 
Tigri thought they had found trichine in the lungs of sheep, but Del- 
pech showed that these were merely the embryos of strongylus filaria. 
Cobbold_ has stated that the trichinge is common in the hedgehog. 
Megnin is convinced that this is an error, and that the worms described 
are merely the eneysted larve of the spiroptera clausa. He showed 
preparations of an encysted nematoid worm, which might easily be 
mistaken for the trichina, but pointed out that the former differs in 
having a papilla at its mouth, and the anus is not terminal. Siebold 
described asatrichina a worm found in cysts in the peritoneum of the 
grey lizard and other creatures, but Megnin asserts that this also is the 
larva of a spiroptera (S. abbreviata), the adult individuals of which are 
abundant in the intestines of thesame animal. An encysted spiroptera 
still more strikingly resembling the trichina has been found in the 
muscles of the frog. Very similar, but larger, encysted worms of the 
same genus have also been discovered in the subcutaneous tissues of a 
bird, the Manchetes pugnax. It will in general be found, however, that 
these parasites exist in the flesh in but small numbers. 
