These formations are very uncommon in the muscular substance of the heart, especially if we refer to cysts containing entozoa. In treating of them, we will limit ourselves to acephalocysts, deferring all notice of the cysticercus till we consider entozoa.

A sac containing acephalocysts is very rarely met with in the muscular substance of the heart, there being only a few cases on record, to which, however, we must subjoin two derived from our own observation. The parent sac contains either one or many aeephalocysts. In one of the cases, we observed only one acephalocyst, which almost entirely filled up the cavity of the parent sac; while in the other, the parent sac, as far as the injured condition of its contents enabled us to judge, was filled with many of these cysts. We are induced, from the rarity of their occurrence, to give a short report of these cases, the former of which was rendered peculiarly interesting from the circumstance, that the presence of these acephalocysts occasioned sudden death. A short notice of the second case, in one of the medical journals, is the only account that has yet been published of either of these two cases.1

1st Case

This case refers to a young woman, aged 23 years, whose sudden death led to a judicial inquiry. The heart was somewhat enlarged and hypertrophied. The uppermost part of the ventricular septum presented a fibro-serous cyst with delicate walls, and larger than a hen's egg, which protruded into both ventricles, but more especially into the right and the conus arteriosus, and had so thoroughly displaced the muscular substance, as to be almost exposed. It had burst over an extent of 1½" towards the right ventricle. From this opening an acephalocyst, nearly equal in volume to the parent sac, had been thrown with the blood into the conus arteriosus and the pulmonary artery, where it was found tightly wedged, and so far within the trunk of the artery as nearly to reach to its left branch.

The liver in this case was very large, and the right lobe contained one acephalocyst of the size of a child's head, and two of about the size of a hen's egg.

2d Case

The heart of a soldier, aged 35 years, was examined; his sudden death being made the subject of judicial inquiry, as in the former case. The posterior and uppermost part of the ventricular septum, and the contiguous portion of the posterior wall of the left ventricle, were occupied by a round sac of the size of a duck's egg, having callous walls of a line in thickness, which projected into the cavities of the right ventricle and auricle. Towards the back of the sac the muscular substance of the heart had disappeared while the heart itself was attached at that point to the pericardium by a dense cellular tissue. On making a section through the wall of the sac, a rust-colored stripe was observed between an outer and inner layer of white fibroid tissue, this stripe being the remains of the peripheral coagulum of a hemorrhagic exudation. The sac contained a pulpy brown fluid intermixed with crumbling and shaggy fibrinous coagula and the soft gelatinous remains of acephalocysts.