A CONTRIBUTION. 
143 
genesis of the same to v. hnmana or ovina. Those exanthemata 
which have been generally looked upon as v. canina, may, in my 
opinion, he more justly considered as symptomatic cutical erup¬ 
tions, which have nothing in common with true variolse. Such 
variola, like exanthemata, frequently accompany the so-called dis¬ 
temper of dogs; they have, however, little resemblance to the 
variolae of the other domestic animals; they continue six to seven 
days, and never form eschara or cicatrices. In other cases v. canina 
is said to possess more resemblance to varicella of man; we must 
not, therefore, leave out of consideration the possibility of the 
transmission of the same to children. When we, however, read 
that in such cases where a dog has 40 to 50 pustules resembling 
those of varicella upon the head, and that grown persons and 
children have, at the same time, suffered from a similar eruption, 
I cannot suppress the suspicion, (which is grounded on much ex¬ 
perience), that in such cases the observers may have had before 
them a parasitic exanthema, such as herpes tonsurans or something 
similar. In other cases the variola-like exanthema, which comes 
to pass by dogs by the transmission of apthm epizootics, and is 
especially located between the toes, may have given occasion to 
complication with variola. Aside from the previously mentioned 
experiments of Greve, I do not know of any other positive exper¬ 
iments in this direction. At least the dog has no susceptibility 
for the contagium of v. humana, except by inoculation, as infec¬ 
tion of dogs by variolse epidemics, where occasions enough are 
given on account of their intimate relations with diseased human 
beings, are as yet unknown. If we inoculate dogs with vaccine, 
we shall develop small bullae tilled with purulent elements, 
which possess an umbo, but only an unimportant pit; in individual 
cases it is reported that positive re-inoculations have taken place 
by children. II am on. 
Variola by the cat has not as yet been reported. 
Several old and new observations are on record with regard 
to variolas by monkeys, according to which in West Indies and 
America, the wild monkeys were affected by variola, when the 
latter was prevailing among the human race. Probably monkeys 
deport themselves towards vaccine in a manner similar to man; 
