REMARKS ON ENTOZOA. 
445 
arise some important questions which must be settled before 
homoeopathists can practise their system safely and success- 
fully. Required, in the case of all medicines, the exact doses 
capable of producing the artifical symptoms which are to con- 
stitute the key to the practical use of the medicine. Required, 
also, in the case of all medicines, the dose in which they 
neither cure any artificial symptoms, nor cure any morbid 
symptoms. Required, lastly, in the case of all medicines, the 
precise limits of the curative dose. 
Edinburgh Veterinary College ; 
July 18th, 1854. 
REMARKS ON ENTOZOA. 
By Robert Dun, V.S., Edinburgh. 
Some very curious and interesting facts have lately been 
discovered by two eminent continental naturalists with regard 
to the animalcule causing sturdy, or staggers, or turnsick in 
sheep. That animalcule (the canurus cerebralis) is one of the 
cystic group of entozoa. It is a being of very simple form — 
consisting merely of a cell, with a double wall, filled with 
colourless fluid. It is attached to the surrounding hardened 
cerebral substance by a double row of incurved hooks, ar- 
ranged round pedunculated heads projecting from the surface 
of the outer wall of the cell. 
The peculiar situation of this animal, and the manner in 
which it has established itself in that situation, have puzzled 
many observers. It is indeed difficult at first sight to ac- 
count for the hydatid’s presence in the body at all, and much 
more so for its lodging itself in the brain more frequently 
than in other organs. But it is well known that, in whatever 
way they reach their destination, different and peculiar 
species of entozoa are found infesting different tissues of the 
body. The observations of Kiickenmeister and Benedin 
afford some clue to the mysterious occurrence of hydatids 
and other entozoa in the bodies of animals. These gentle- 
men found that the hydatids of the sheep’s brain, when in- 
troduced into the alimentary canal of the dog, were developed 
into tapeworms or tania. And again, by a converse process, 
they discovered that when healthy sheep swallowed the 
segments of canine tapeworms distended with ova, hydatids 
were developed in their brains in about a fortnight. From 
these experiments it would appear that the coenurus cere- 
bralis and tapeworms are convertible. In fact, we might 
