COMPARATIVE ANATOMY. 
“ Transactions of the Linnaean Society.” 
vol. 3. 
These animals, which are called botts, 
attach themselves to every part of the sto- 
mach, but are in general most numerous 
about the pylorus ; and are sometimes, but 
much less frequently, found in the intes- 
tines. They hang most commonly in clus- 
ters, being fixed by the small end to the in- 
ner membrane of the stomach, where they 
adhere by means of two small hooks or ten- 
tacula. When removed from the stomach, 
they will attach themselves to any loose 
membrane, and even to the skin of the 
hand ; for this purpose they draw back 
their hooks almost entirely within the skin, 
till the two points of these hooks come 
close to each other; they then present 
them to the membrane, and keeping them 
parallel till it is pierced through, they ex- 
pand them in a lateral direction ; and after- 
wards, by bringing the points downwards, 
or towards themselves, they include a suf- 
ficient piece of the membrane with each 
hook, and thus remain firmly fixed, for any 
length of time, without any further exer- 
tion of the animal. They attain their full 
growth about the latter end of May, and 
are coming from tlie horse from this time 
to the latter end of June. On dropping to 
the ground, they soon change to the chry- 
salis, and in six or seven weeks the fly ap- 
pears. This bott is larger and whiter than 
that of the oestrus haemorhoidalis, which has 
a reddish cast ; but in its structure, and si- 
tuation in the animal, resembles the former. 
It is found, however, to hang about the 
rectum, previously to quitting it, which the 
large horse-bott never does. 
Veterinary practitioners do not seem to 
have decided hitherto, whether these animals 
are prejudicial to the horse ; nor even whe- 
ther they may not be actually beneficial. 
Their almost universal existence at a cer- 
tain season, even in animals perfectly 
healthy, shows that they produce no mark- 
ed ill effect: yet the holes which they 
leave, where they were attached to tlie sto- 
mach, could hardly be made without caus- 
ing some injurious irritation. 
For the mode in which these botts gain 
admission into the stomach, as also for a 
most interesting general account of their 
history and structure, see CEstrus, which 
was furnished by Mr. Clark, and from 
which the preceding account is bor- 
rowed. 
The food of carnivorous animals ap- 
proaching in its constituent elements more 
nearly to those of the animal than that of 
the herbivorous tribes, is more easily re- 
duced into the state which is required for 
the nourishment of the body, in the former 
than in the latter case. Hence arises a 
leading distinction between the stomachs 
of these classes. In the latter animals, the 
oesophagus opens considerably to the right 
of the great extremity, so as to leave a 
large cul de sac on the left side, of the sto- 
mach ; and the small intestine commences 
near the cardia, leaving a similar blind bag 
on the right. The food must be detained 
for a long time in such a stomach, as the 
pas.sage from the oesophagus to the pylorus 
is indirect and highly unfavourable to 
speedy transmission. Animals of the mouse 
kind, and the rodentia, show this structure 
very well ; it is very remarkable in the mus 
quercinus, (Cuvier, “ Lemons,” &c. tom. 5. 
pi. 36. fig. 11). In the carnivora, the sto- 
mach, which is of a cylindrical form, has no 
cul de sacs ; the oesophagus opens at its an- 
terior extremity, and the intestine com- 
mences from the posterior; so that every 
thing favours a quick passage of the food. 
Animals of tlie weasel kind, which are very 
truly carnivorous, exhibit this structure the 
most completely. The seal also exempli-- 
ties it, and the lion. (Cuvier, pi. 36. fig. 7). 
The most complicated and artificial ar- 
rangement, both with respect to structure 
and mechanism, is found in the well-known 
four stomachs of the ruminating animals 
with divided hoofs ; of this we shall take, as 
examples, the cow and sheep. 
The first stomach, or paunch, (rumen, 
penula, magnus venter, ingluvies), is by far 
the largest in the adult animal ; not so how- 
ever in the recently born calf or lamb. It 
is divided externally into two saccular ap- 
pendices at its extremity, and it is slightly 
separated into four parts on the inside. Its 
internal coat is beset with innumerable flat- 
tened papillae. 
This is followed by the second stomach, 
honeycomb bag, bonnet, or king’s hood, 
(reticulum, ollula), which may be regarded 
as a globular appendage of the paunch; 
but is distinguished from tlie latter part by 
the elegant arrangement of its internal coat, 
which forms polygonal and acute-angled 
cells, or superficial cavities. 
The third stomach, which is the smallest, 
is called the manyplus, which is a comip- 
tion of manyplies (echinus, conclave, centi- 
pellio, omasum) : it is distinguished from 
the two former, both by its form, which has 
been compared to that of a hedgehog when 
