Of the species entitled Echinococcus veteri minion we have carefully examined several in dividuals soon after they were extracted from the recently-killed animal, (a sow, in which they existed in great abundance in cysts in the abdomen.) The containing cysts were com posed of two layers, artificially separable, both of a gelatinous texture, nearly colourless and subtransparent, the external one being the firmest. The contained fluid was colourless and limpid, with a few granular bodies floating in it, and immense numbers of extremely mi nute particles applied hut not adherent to the internal surface of the cyst. On examining these particles with a high magnifying power, they were seen to he living animalcules of an ovate form, moving freely by means of superfi cial vibratile cilia, having an orifice at the smaller end from which a granular and glairy substance was occasionally discharged, and a trilobate de pression at the greater and anterior extremity produced by the retraction of part of the body. I watched attentively and for a long period a number of these animalcules in the hope of seeing the head completely protruded, but with out success. On compressing the animalcule: between plates of glass, a group of long, slen der, straight, sharp-pointed spines became vi sible within the body, at its anterior part, and directed towards the anterior depression, pre cisely resembling the parts described and fi gured by Ehrenberg as the teeth of the Poly gastric Infusories ; the rest of the body was occupied by large clear globules, the stomachs? and smaller granules. Animalcules thus orga nized, it is evident, cannot be classed with cystic Entozoa, but must be referred to the Polygastric Infusoria.
The globular cyst which is commonly deve loped in the brain of Sheep differs from the Echinococcus in having organically attached to itanumber of small vermiform appendages, pro vided severally with suctorious orifices, and an uncinated rostellum, similar to those in the head of the Armed Twnim. But as this cystic genus, denominated Ca'nurus, (xonoc, communis, cauda, from the terminal cyst being common to many bodies and heads,) is not met with in the human subject, a simple notice of it is here sufficient.
When the dilated cyst forms the termina tion of a single Entozoon, organized as above described, it is termed Cystieereus, (xvcrric, vesiea, xspxoc, cauda), and of this genus there are several species, distinguished for the most part by the forms and proportions of the neck or body intervening between the head and the cyst ; as for example, the Cyst. fitsciolaris, Cyst. fistularis, Cyst. longieollis, Cyst. tenuicollis, &c. The only species of this genus known to infest the human body is the Cystieereus eellulosee, Itud. (the Hydutis Finna of Blumenbacli). It is developed, like the Trichina, in the interfaseieular cel lular tissue of the muscles, and, like it, is in variably surrounded by an adventitious cap sule of the surrounding substance condensed by the adhesive inflammation. Fig. 59 exhi bits a portion of muscle thus infested; a the adventitious cyst laid open, exposing the datid ; a' the adventitious cyst elongated by the extension of the head and neck of the inclosed hidatid b in the direction of the muscular fibres.
the eysticereus itself sometimes attains the size exhibited in fig. 60, in which a indicates the head, b the neck or body, and c the dilated vesicular tail. Fig. 61 exhibits the head sufficiently magnified to show the uncinated rostellum or proboscis d for irritation and adhesion, and the suctorious discs e e for im bibing the surrounding nutriment.
The occurrence of this Entozoon in the Hu man Subject appears to be less common in this country than on the Continent. In the course of five years we have become acquainted with only two cases, one in a subject at the Dis secting4tooms of St. Bartholomew's, the other in a subject at the Webb-street School of Ana tomy. Itudolphi relates that out of two hun dred and fifty bodies dissected annually at the Anatomical School of Berlin, from four to five were found through nine consecutive years to be infested more or less copiously with the Cyslicercus cellulose ; for the most part the subjects had been of the leucophlegmatic temperament, but not affected with ascites or anasarca. The muscles most obnoxious to the Entozoon in question are the glutcei, psoas, iliacus internus, and the extensors of the thigh ; they have been found also in the muscular tissue of the heart, and in parts not muscular, as the brain and eye. Soemmering detected one specimen of the Cysticercus cellulose in the anterior chamber of the eye of a young woman at. 18.* The following is a more re cent account of a specimen which was deve loped in the anterior chamber of the eye of a patient in the Glasgow Ophthalmic Infirmary.
" Case.—From the month of August, 1832, till about the middle of January, 1833, when she was first brought to Mr. Logan, the child had suffered repeated attacks of inflammation in the left eye. Mr. L. found the cornea so nebulous, and the ophthalmia so severe, that he dreaded a total loss of sight. Ile treated the case as one of scrofulous ophthalmia ; and after the use of alterative medicines, and the appli cation of a blister behind the ear, the Main matory symptoms subsided, leaving, however, a slight opacity of the lower part of the cornea. After a week, the child was again brought to Mr. L., who, on examining the eye, disco vered, to his great surprise, a semitransparent body, of about two lines in diameter, floating unattached in the anterior chamber. This body appeared almost perfectly spherical, ex cept that there proceeded from its lower edge a slender process, of a white colour, with a slightly bulbous extremity, not unlike the pro boscis of a common fly. This process Mr. L. observed to be of greater specihc gravity than the spherical or cystic portion, so that it always turned into the most depending position. lie also remarked that it was projected or elongated from time to time, and again retracted, so as to be completely hid within the cystic portion ; while this, in its turn, assumed various changes of form, explicable only on the supposition of the whole constituting a living hydatid.