21 
very frequent in horses that have been at grass, and are in general 
found adhering to the white insensible tissue or coat of the sto¬ 
mach which comes from the lining of the oesophagus, and which in 
extending or leading over the upper part of the stomach, repre¬ 
sents, or is similar to, the maw or first stomach of the ruminating 
animals. I do not recollect ever seeing many situated on the red 
membranes of the stomach, which are, without doubt, more 
sensible, and where their effects would have been more disagree¬ 
ably felt. 
They make small deep round holes where they adhere to this 
white tissue, and sometimes so deep as to pass through it but not 
through the other layers or coats of the stomach, as has been often 
hastily apprehended and asserted, that they are probably but lit¬ 
tle felt by the animal. In proof of this, I once gave six, and after¬ 
wards twenty-seven, of the full grown Larvre to a horse, wrapt up 
in balls of meal, but the horse by no external indications showed 
any uneasiness in consequence. 
They usually hang in dense clusters to this white cuticular 
linin« of the stomach, and maintain their hold by means of two 
dark brown hooks, (see fig. 10, Plate I.) between which a longi¬ 
tudinal slit or fissure is seen, which is the mouth of the Larva. 
When removed from the stomach by the fingers by a sudden jerk, 
so as not to injure them, they will, if fresh and healthy, attach 
themselves to any loose membrane, and even to the skin of the 
hand. For this purpose they sheath or draw back the hooks 
almost entirely within the skin, till the two points come close to 
each other ; they then present them to the membrane, and keep¬ 
ing them parallel till it is pierced through, they expand them in 
a lateral direction, and afterwards, by bringing the points down¬ 
wards towards themselves, they include a sufficient piece of the 
membrane, to remain firmly fixed for any length of time as at an¬ 
chor, without requiring any further exertion. 
These hooks, the better to adapt them to this purpose, appear 
F 
