310 The American Naturalist. [April, 
sporules, which, in their turn, also become free, and myriads 
of young sporozoa are soon formed. These possess the “ power 
of insinuating themselves into the protoplasm of epithelial 
cells, where they grow and become transformed into oval para- 
sites resembling the adult form” [Metschnikoff]. In course 
of time, the epithelial cell wall is ruptured and the parasite 
escapes, without necessarily causing the destruction of the pest 
cell; it passes through the alimentary canal, gains access to 
the atmosphere, and thus attains the conditions necessary to 
recommencing its cycle of development. Having been shown 
the life history of the coccidian parasite of the rabbit,” we shall 
be better prepared to recognize the [apparently] kindred dis- 
ease in man and some of the higher vertebrates. “Taking 
eancer of the breast as an example,” says Dr. Galloway, “if 
careful microscopic examination is made, there will be found 
lying, most commonly within the cell body, rounded or oval 
structures varying in most cases from 2 + to 10 » in diameter, 
having, when large, a very distinct capsule, and containing a 
smaller body of variable shape. From the capsule there may 
be seen passing towards the centre numerous fine radial stria- 
MONG, e ig. 4 ene processes of a somewhat different char- 
acter may also be seen passing from the nucleus towards th 
periphery; they are not so regular and appear to be prolong- 
ations of the nucleus. 
“These bodies occur sometimes singly, sometimes in twos 
and threes, and occasionally to the number of nine or ten—and 
even twenty,’ of small size—in a single cell. In a successful 
preparation each of the small ones will be seen to contain the 
usual nuclear substance (see Figs. 3 and 4). Similar structures 
of smaller size may be observed lying inside the nucleus of the 
epithelial cells. In this ease the capsule, so very characteris 
tic of the intracellular bodies, is very slight, and indeed, ap- 
pears to be absent in most cases. “The intra-nuclear bodies 
also occur either singly or in small groups.” Occasionally the 
*S-:e also Fig. XVII, Sporozoa; Gregarinide article Protozoa, Encyclopedia 
Britannica, pp. 852-3. i 
i M. D., 
‘‘ I have seen over 20 parasites in the same nucleus.” —M. Armand Rufter, 
B. Medical Journal, Nov. 5, 1892. 
