214 NATURAL HISTORY MISCELLANY. 
Dr. T. M. Brewer is engaged in preparing for the press the second 
and last part of the North American Odlogy, the first part of icon 
appeared in volume seven of the Smithsonian ‘‘ Contributions.” 
eggs and nests of about one hundred and fifty birds will be desende 
The illustrations will consist of about one hundred figures, in five or 
six 4to plates 
p 
We have received some advance sheets of a work on the Ornithology 
and Oölogy of New England. By Edward A. Samuels. Nichols & 
Noyes, Boston. e shall give a farther notice of it hereafter. It 
will contain over five hundred 8vo pages, and be illustrated by twenty- 
three plates of Birds, four plates of Eggs, and a large number of 
wood-cuts. 
ceo ety ae 
CORRESPONDENCE. 
In answer to several inquiries regarding the disease resulting from 
eating pork infested by the Trichina, we print the following account 
wien pre KE for the Naturalist by a well-known authority on this 
subje 
Printia spiralis. — This entozöon is the cause of a serious and often 
fatal disease of the intestinal canal and muscular system of man, called 
Trichiniasis or Trichinosis, which is produced by eating the flesh of 
pies similarly affected. Before giving an account, however, of the 
natural history of this parasite, it may be well to state that trichinous 
us is not measly pork. Measles in the hog is the encysted stage of 
the common tape-worm of man (Tenia solium). Measly flesh being 
eaten, the little cysts or scolices, as they are called, which consist of 
e future head of the mature animal inverted, escape from their sacs 
within the stomach, unless previously destroyed by cooking, and at- 
tach themselves by their armed heads to the intestinal walls. From 
this head are developed one after another the joints which make up 
the body of the tape-worm. The first formed or oldest pe or 
proglottides, when sexually mature, escape from the intestinal c€ 
of their host, and, being eaten by swine, the ova they contain are sS a 
free. During digestion, the eggshells are dissolved, and the minute 
embryos find their way into the tissues of their new host, to be again 
converted into encysted scolices, or measly pork. In this stage the 
tape-worm is called Cysticercus cellulose 
The Trichina spiralis, on the other biah does not belong to this 
order of Cestoidea or encysted worms, but to the Nematoidea or 
round worms (of which the pin-worm is an example), and its develop- 
‘ment is much less complicated. If trichinous pork is examined by the 
microscope, the muscular fibres will be found occupied by minute 
