TRICHINA SPIRALIS. T 
of practice are concerned. But with a good clear lens, even this 
power enables us to distinguish the coiled-up form of the worm, 
from which they derive their specific name spiralis. Let us now 
follow the changes which take place when such a piece of meat is 
eaten. As seen in the flesh shown in Figure 2, the living worms are. 
enclosed in bags or cysts, one of which is shown more highly mag- 
nified in Fig. 3. In time these cysts become 
coated with a calcareous deposit, so that, 
the worms are literally entombed in marble 
coffins. At first this probably serves to 
protect them. Worms in this condition, 
therefore, are incapable of doing further 
harm ; their career of mischief, so far as 
they themselves are concerned, is ended. But when the flesh in 
which they are embedded is eaten and digested, the capsules are 
dissolved, and the worms are set free to move about in the stomach 
