of the subject should consult the larger treatise referred to in my preface.

The armed tapeworm, as has now been known for many years past, is derived from pork; or rather, in other words, we obtain it by eating the so-called 'measly' flesh of swine. A general impression prevails, that all human tapeworms have a similar origin, but without entering into particulars, I may state, once for all, that such a notion is entirely groundless. Every tapeworm has its own special form of larva, and the larva itself is as distinctive as is its own peculiar adult parent. Every fullgrown tapeworm has an appetite, so to say, for a certain kind of residence, and, as in the species under consideration, usually confines itself to one particular kind of bearer. It may almost be said that every tapeworm has its own 'host' or 'bearer,' and consequently also, that every bearer carries, or is liable to carry, his own tapeworm. Very contrary, indeed, does it appear to the presumed dignity of the human species, that man should be, as it were, singled out as the legitimate home and territory of a tapeworm; but not only is this the case, but

science almost teaches us to aver that, so far as this life is concerned, man appears to have been made expressly for the accommodation of certain tapeworms. At all events, without man, two apparently distinct species of tapeworm could not, it would seem, exist. The armed tapeworm has never yet been found in any 'host' save man, and the same may be said of the unarmed human species. Of course, in making the above statement as regards cause and effect, I am only, for the time, adopting the ordinary mode of teleological reasoning; but however logical the deduction may at first sight appear, I need not say that I can hardly bring myself to believe in the correctness of such a conclusion.

The perfect armed tapeworm, as it is usually presented to the observer, is a long, soft, whitish, jointed animal, which, when alive, elongates and contracts itself with great facility. Though commonly spoken of as a single animal, it is in truth a compound of many individuals. These individuals are called 'cucurbitini,' 'zooids,' or 'proglottides,' by scientific persons, and they are likewise occasionally termed links,

or joints. By whatever name they are called they represent so many distinct segments of the body, and, when fully grown, they are capable of detaching themselves

and of enjoying a free and independent existence. Very annoying it is to the human bearer to be continually reminded by his unwelcome guests' that, for their own pleasure or lifenecessities, they desire to quit his interior. Not, indeed, do they oblige him by departing

FIG. 2.

all at once; but their habit is portion of the body

to wander, solitarily and in suc

cession as it were, as if

pur

posely to plague his very life

of Taenia solium, with a naturally produced knot. (b) Reproductive papilla.

out.' This expression is one which is not uncommonly used by persons thus afflicted; and I have seen one or two individuals so emaciated by the discomforts arising from the presence of tapeworm, that in reality life itself had almost been plagued out.' To say the least, such individuals have wished themselves deprived of existence.

The head of the armed tapeworm is characterised by the possession of four sucking disks

Head of Taenia solium viewed from square-shaped head,

above (A) and in front (B). En

larged, and drawn with the aid of a the rostellum being

camera. Original.

situated at the cen

tre and summit. In the projected state this process has the form of a cone whose base supports two rows of hooks. Each row carries from twelve to fourteen hooks, so that there are usually twenty-four or twenty-eight altogether. The size of the head is equal to that of a small pin-cap. It is succeeded by a long narrow neck, finely striated transversely. These striæ represent the future segments of the body, and at a distance of about one inch and a half from the head, their joint-like character can be detected with the aid of a pocket lens. Further down, the joints soon acquire their characteristic individuality, and at about the four

hundred and fiftieth segment their internal sexual organs become fully developed. In a

Head and neck (B), and one of the sexually mature joints (A) of Tania solium (after figures by Blanchard), showing more particularly the branched egg-bearing organ (o) filled with ova. It also shows the oviducal canal (o'), the cirrhus (t), and the external outlet (t). Enlarged.

fully grown worm we may count as many as twelve hundred segments, that is, including the