600 Abstract Report of Agricultural Discussions. 
rare specimen is the bothriocephalus, so termed from its having a- 
peculiarly formed head. The example produced was obtained some 
years ago from a dog. It is a variety of tape-woi-m not common in 
this country, but which exists among the inhabitants of Sweden, 
Norway, and the North of Europe. It measures seven feet long ; 
and the dog fi-om which he took it had been the subject of cutaneous 
disease, which probably depended upon the presence of this worm in 
the intestinal canal, where it kept up a perpetual irritation. The 
cause of rot in sheep is to be found in the existence of the sterel- 
xninthal variety of entozoa — the distoma hepaticum. 
Hollow Woems, 
The third class — the coelelmintha, or hollow worms — are those with 
which we are most familiar. It includes the filaricB, or thi-ead-worms, 
and among these are the filaria oculi, existing in the eye of the horse 
in India. Another worm, existing in sheep, and producing sym2)tom8 
analogous to rot, inhabits the stomach, and di-aws largely upon the 
nutriment of the animal. It inserts its head, which is armed with 
barbs, into the mucous membrane, where the barbs enable it to hold 
on, or, by closing them, to withdraw its head at pleasm-e. To this I 
have given a name — filaria hamata — the hooked or barbed thread-worm. 
There is likewise the filaria hroncliialis, found within the bronchial 
tubes of calves and sheep in particular, which produces that form of 
disease designated " husk." This is the most common of the lot, and 
is to be met with in the bronchial tubes of every domesticated animal 
— ^in colts, in calves, in sheep, in pigs, and even in dogs. But it is in 
the herbivorous animals that the worm produces the greatest amount 
of mischief, and particularly with ruminating animals, calves and lambs; 
for all young animals are far more predisposed to the attacks of parasites 
than the old. I exhibit one example taken from a calf ; another from a 
pig, in which the worms are crowded together in countless numbers in 
the ramifications of the bronchial tubes. Of late yeai-s this worm has 
excited a gi'eat deal of notice on the pai't not only of the pathologist, 
but of the practical farmer, in consequence of the sad losses which have 
resulted fi-om its presence amongst flocks of lambs. At the present 
time a considerable number of lambs are aifected with it, and within the 
last ten or twelve years the losses have been really very serious. It is 
very difficult to say why there has been of late an increase of entozoic 
diseases. Whether it has arisen from any particular condition of the 
atmosphere which was favourable to their propagation, he could not 
say ; nevertheless, the fact is well established. 
The natural history of these filarife is by no means difiicult to under- 
stand. They exist in the form of perfect males and jicrfect females ; the 
sexes, however, are by no means equal, the females being as 50 or 60 to 
one. This worm is one of those creatures which may be called ovo- 
viviparous ; for occasionally it will happen that the young worm is so 
perfected while the ovum is within the body of the female that it 
escapes from the egg, and exists as a living worm before passing 
through the so-called ova-duct. 
