140 
F. S. BILLINGS. 
I 
an offshoot, produced by the wanderings of the contagium of v. 
liumana or ovina, perhaps also of vaccina, to swine. When an 
evidently infectious disease appears so seldom as v. porcina, while 
its genesis has been proven in single cases from v. ovina or liu- 
inana, and when we cannot concede an obiogenetic development 
for the same, then everything must force us to the conclusion 
that v. porcina must take its origin from other forms of variola, 
ovina, vaccina or liumana. 
We will now proceed to consider the other main alveolic group, 
viz; the localized variolie of cattle, horses and goats, and shall 
follow the same with consideration of variolse by the dog, monkey, 
hare, camel, and domestic fowls. 
Variolae equina} have won an undeserved importance in 
that Jenner sought in them the origin of variolee vaccinse. 
By the great infrequency of this form of variola, at least in 
Germany, one looks in vain for exact and good descriptions of the 
same. [I must be excused from introducing an exact translation 
of the next few words, as I do not see any better form to put 
them into (B.).] I show you here two wax preparations from 
Sacco, which represent equina in different stages of development. 
Upon the pastern of one foot you see variolm in the stadium of 
eruption, on the second in that of suppuration. You may also see 
two strongly prominent places which are hairless, the one as large 
as a 25c piece, the other as large as a silver dollar, slightly hyperse. 
mic, and appearing somewhat like a pseudo-erysipelas upon the hu¬ 
man finger. This erysipelatous tumefaction of the posterior face of 
the pastern is primarily hot and painful, and soon presents a moist 
surface. The infectious, sometimes pustulous exanthema generates 
by inoculation of its pathological product, equine, pure vaccina by 
cattle, and by man an exanthema resembling that produced by 
vaccine (Lafosse, Bouley, Depaul); by vehicles or harness—the ex¬ 
anthema may be extended to other horses. 
The circumstance which at first appears remarkable, that 
variola is as a rule by the horse, represented by an erysipelatous 
or eczematous exanthema in the vicinity of the pastern, finds an 
easy explanation, when we remember, that the parts in question 
are frequently the subject of injuries or erosions which especially 
