228 ON POULTRY LOUSINESS IN THE HORSE. 
describe ! The name of poultry phthyriasis, proposed by us to 
designate it, in itself shews in what pathological light we view 
it. In fact, we believe that it is the ova of the lice with which 
fowls are infested in such multitudes that, hatching by myriads 
upon the horse’s skin, occasion the especial irritation of which 
it becomes the locality, producing the eruption of confluent ve- 
sicles upon its surface, with consecutive depilation. Every 
thing conspires to strengthen this our belief. The sudden ap- 
pearance of the ailment; its instantaneous propagation over the 
entire tegumental surface; the annoying, even tormenting itch- 
ing, with the evening exacerbation accompanying the irritation; 
and, above all, the occurrence of all this at a time alone when 
horses are living in the same locality with fowls, from which 
they contract it; and that it is sufficient, to make the disease 
disappear, to remove out of the influence of the ostensible cause. 
No doubt, the demonstration of this etiological fact will not 
receive satisfactory testimony until one or other of the varieties 
of lice known to harbour about fowls comes to be seized upon 
the skin of the horse, a proof which we must avow is as yet 
wanting, though the lack of it, no doubt, is owing to the insuf- 
ficiency of our means of exploration, as well, perhaps, to the too 
remote period at which the majority of subjects infested from lice 
are brought to us. Mayhap, when we come to make observations 
on subjects the moment they shew symptoms of infection, having 
a good microscope to examine the epidermic dirt collected upon 
the surface of the skin supposed to be lousy, we shall discover, 
not the insect at its full development, in the form it is seen 
by the naked eye upon the fowl’s feathers, but the microscopic 
insect, such as it appears at its exit from its ovum, already pos- 
sessing great vivacity, with all its organs complete. For lice 
constitute an order of the insect tribe which are not subject, 
properly speaking, to metamorphosis. They quit their eggs 
with every external attribute belonging to the older animal; 
the only difference being in their comparative development. 
So that it is possible the disease may declare itself at the very 
moment of the hatching of the ova, and that it may become 
perpetuated by successive hatchings ; since it is still question- 
able whether insects from either fowls or pigeons can live and 
propagate upon the horse’s skin. At this moment we are en- 
gaged in experimenting on this interesting question. 
The treatment of poultry phthyriasis, or lousiness, is very 
simple. The first indication is to remove the subject away out 
of the influence of the ostensible cause. The hair should then 
be clipped off, especially if the coat be long and thick ; which 
done, some alkaline lotion may be brushed into the skin ; or 
an infusion of tobacco — one lb. to six or eight pints of either 
