HYDATID IN THE SPINAL MARROW OF A LAMB. 285 
he had once been led to think that hydatids always formed upon 
the brain in sheep ; but he had since found them occur within it. 
On one sheep he made the following- experiment:—He took out 
a portion of bone with the trephine, and on cutting* through the 
dura mater, a very large hydatid partially protruded. This he 
attempted to extract, but the cyst broke in the trial. He after¬ 
wards extracted the cyst, and upon looking through the opening 
made with the trephine, he found the interior to present a large 
empty cavity; the brain appeared completely gone. He then 
let down a light through the opening into the cavity of the skull, 
by which it appeared that nearly the whole of the cerebrum w as 
wanting. The opening being afterwards closed, the sheep got 
up and fed, and seemed better for the three following days, but 
on the morning of the fourth he found it lying convulsed, in 
which state it soon died. Upon opening the head, he found a 
little of the cerebrum at the base, and some remains at the sides, 
forming an imperfect shell of brain ; there were several other 
smaller hydatids remaining. From this Mr. Stephens concluded, 
that when an operation succeeded in these cases, it must be 
where there was only a single hydatid, and where there w as but 
little disorganization of the brain : he agreed in opinion, therefore, 
with those w ho thought there was a better prospect of success 
in operating in acute than in chronic hydrocephalus; because in 
the former there was no particular disorganization of the brain 
accompanying the collection of fluid, whilst in the latter, por¬ 
tions of the brain were in many instances destroyed ; and in such 
cases, even if you could preserve life, you could not preserve 
or repair the intellect. Sir Astley Cooper once shewed Mr. Ste¬ 
phens a ewe of his, where he had opened an hydatid and dis¬ 
charged the water, and in which case the animal had recovered, 
and had afterwards borne a lamb.— (Lancet) 
An Hydatid in the Lumbar Portion of the Spinal 
Marrow of a Lamb aged eighteen Months. 
By M. Dupuy. 
This lamb w as in a state of extreme emaciation. It could not 
stand on its hind legs, which were devoid of feeling and motion, 
and it constantly lay down. On opening the animal an hydatid w r as 
found in the grey substance of the lumbar region of the spinal 
marrow. This worm, about the size of a goose-quill, and half 
an inch in length, was composed of a thin transparent membrane, 
resembling a spider s web, and presented on its surface many 
