144 
POPULAR SCIENCE REVIEW. 
parasite were shown to the Society on the 19th of March, 
1853, by Dr. W. T. Gairdner, who, with his usual acuteness, 
declared that the whole appearance of the parasite was such 
as seemed strongly to bear out Oweir’s view, that the trichina 
was merely the first stage of an animal destined for further 
development. Dr. Gairdner thought it very probable that 
the muscle was only the hot-bed of ova, which, for their 
development into perfect animals, required some other habitat. 
Considering it to be not unlikely that this further development 
of trichina might take place in the intestinal canal of some 
carnivorous animal, Dr. Gairdner sent some of the specimens 
exhibited, in the fresh state, to Mr. Barlow, who administered 
portions to dogs and cats;* and I learn from Dr. Mercer 
Adam that the result of the experiments was as anticipated 
by Dr. Gairdner. The results were not published, and we 
owe to continental observers and to Mr. Turner, of the Edin- 
burgh University, interesting information as to the propagation 
of the parasite. 
Professor OweAs first description is in many points com- 
plete. In his paper communicated to the Zoological Society of 
London he says : “ With a magnifying power of an inch 
focus the white specks in the muscle are seen to be cysts of 
an elliptical figure, with the extremities in general attenuated, 
elongated, or more opaque than the body (or intermediate 
part) of the cyst, which is, in general, sufficiently transparent to 
show that it contains a minute coiled-up worm. On separating 
the muscular fasciculi, the cysts are found to adhere to the 
surrounding cellular substance by the whole of their external 
surface, somewhat laxly at the middle dilated part, but more 
strongly by means of their elongated extremities, so as to 
render it generally a matter of some difficulty to detach them. 
When placed upon the micrometer they measure inch in 
their longitudinal and inch in their transverse diameter ; 
a few being somewhat larger, and others diminishing in size 
to about one-half of the above dimensions. They are generally 
placed in single rows, parallel to the muscular fibres, at dis- 
tances varying from half a line to a line apart from one 
another ; but sometimes a larger and a smaller cyst are seen 
attached together by one of their extremities, and they are 
occasionally observed slightly overlapping each other. If a 
thin portion of muscle be dried and placed in Canada balsam, 
between a plate of glass and a plate of talc, the cysts become 
more transparent, and allow of the contained coiling-up 
worm being more plainly seen. 
“ Under a lens of the focus of half an inch, the worm appears 
* The Monthly Journal of Medical Science, vol. xvi., 1853. 
