THE RAY-WORM. 539 
piece of wood or pasteboard, rolls the projecting end of the worm round it, and, after very 
cautiously drawing it out for a few inches, he winds up the loosened portion, and ties the stick 
close to the limb. Next day, he draws out a little more of the worm, and proceeds in a simi- 
lar manner, until, in a fortnight or three weeks, the entire entozoon has been withdrawn and 
wound upon the roller. 
This process is extremely simple, but demands the greatest care, as, if the worm should 
be broken, a most painful and even dangerous tumor is certain to arise. I have seen a moder- 
ately large specimen of the Guinea Worm extracted from an English sailor, into whose leg it 
had made an entrance, and who was quite incapable of work until his enemy had been 
destroyed. It is rather flat, like some kinds of silken thread, and is of a very pale brown 
color. 
Passing by a few genera, such as Ascaris, Tricocephalus, and Strongylus, all of which are 
found in the human subject, we come to the large and important genus Teenia, which may be 
accepted as the type of all the Entozoa. The well-known Tape-worm (Z@nia solium) belongs 
to this genus. It derives its name of sodium, as also its French title of Ver Solitaire, from the 
supposed fact, that only one individual can infest the same person. It is, however, known 
that a few cases have occurred where the same individual has been afflicted with at least two 
specimens of Tape-worms. Those which belong to this genus may be known by the long, flat 
body, and the head with four suctorial spots, and almost invariably a cirele of very small but 
very sharp hooks. The whole structure of the Tzenia is interesting to those who study com- 
parative anatomy, but too purely scientific to be described in these pages. 
Another species of Tape-worm that is found in the common cat is termed Tenia crassi- 
collis. An example of a Tape-worm that is found in several birds, such as the nightingale, 
blackeap, and the lark, is called, after the jast-mentioned bird, Lark-worm (Zenia platy- 
cephala). Another species of this is found in the black-backed gull. 
_ Tenia, Tape-worm, is a parasitic worm of flattened, tape-like form, living in the intes- 
tines of man and many of the lower animals. The long, tape-like creature is made up of many 
joined together, each joint being regarded as a distinct animal. 
The Tenia solium is the more familiar form. In a tolerably healthy person it may remain 
parasitic during a long period. 
The treatment for this pest is aimed to dislodge the head ; for, if that is left, though all 
of the body, its numerous joints, be thrown off, the head isa nucleus or starting-point for 
more, and the disease becomes as troublesome as before. Once the head is dislodged, there is 
an end of the creature. Pomegranate root and the extract of the root of the male fern are 
regarded as the most efficient remedies. 
There is another notable genus of Entozoa, commonly going by the name of Hydatids, on 
account of the large amount of liquid which is found within their cells. Within each large 
cyst, or cell, myriads of smaller cysts may be found, some in an early stage of progress, and 
others being further advanced, and containing other cysts within themselves. 
T have seen some enormous Hydatids taken from the interior of a female monkey. They 
were so large and so full, that the owner of the animal thought that it had died from over- 
eating itself. On opening the creature, however, the stomach was found to contain very little 
food, and almost the whole cavity of the chest and abdomen was filled with huge cysts, which 
had encroached upon all the vital organs, pushed the heart on one side, enveloped the whole of 
one lung, and, in fact, had caused so strange a disturbance of the viscera, that the fact of the 
creature having supported life under such circumstances seemed almost incredible. The large 
cysts contained a vast number of smaller cells, and these again were filled with cysts of still 
less dimensions. A large quantity of fluid also existed, and floating in the liquid were found 
myriads of echinococci, very small, but with the characters exhibited perfectly well under the 
microscope. 
WE now come to our last examples of the Entozoa. 
The Ray-worm is, as its name imports, an inhabitant of fishes belonging to the ray tribe. 
The genus to which.this creature belongs is a rather remarkable one, the head affording some 
