480

REPORT ON ZOOLOGY, MDCCCXLIV.

became more constant. She could scarcely walk alone, froma frequent tendency to stagger. The pain in the headbecame constant, though never extremely acute; her sightbecame dim, and, after frightful convulsions, she expiredtowards the end of October 1840. On examination afterdeath, the vessels on the surface of the brain were foundmoderately congested, and the sub-arachnoid cellular tissuewas infiltrated with serum; but the most remarkable morbidappearance which the organ exhibited arose from the pre-sence of numerous small fibrous cysts in the pia mater,covering the surface of the hemispheres, and dipping be-tween the convolutions of the brain. These cysts werepresent on both sides, but were most numerous on thesurface of the left hemisphere. They varied in size fromthat of a pea to that of a small peppercorn ; they wereseated in the pia mater, but had become partially imbeddedin the gray matter of the convolutions. None existed inthe white matter, in the central ganglia, nor in the plexuschoroides. A few were found at the under surface of thecerebral convolutions; but none either in the cerebellum ormedulla oblongata. The cerebral tissue around the cystsappeared natural, as to colour and consistence, and thebrain generally, except for the presence of these animals,would have been termed healthy. There was, it should beadded, however, rather more fluid in the ventricles and at thebase of the brain than is natural. No traces of the para-sitic animals were found in the chest. Several of the cystswhich had been removed were afterwards examined, andeach was found occupied by a vesicular worm, consisting of aposterior semi-transparent vesicle, and an anterior cylin-drical portion, which lay retracted in the former, like thefinger of a glove turned inwards; the latter part was fur-nished at its extremity with a double circlet of hooks, roundwhich were seen four oval suckers. The animal, in short,answered exactly to the Cysticercus cellulosa of Rudolphi.In some of the cysts the animal had evidently perished andwas undergoing decay, but still retained sufficient traces of