398 
OBSERVATIONS ON PORRIGO OR TINEA. 
the application of the contagious material, one irregularly 
circular crust, semi-transparent dark yellow in colour, 
covered the spot where the three introductory achores-or/kw 
had been. 
What rendered this the most attractive and interesting of 
the series of experiments, however, was the fact that an 
isolated achor or favus appeared at the root of one of the 
claws of the left fore foot. The earlier stages of the disease 
on the head seemed to he accompanied with considerable 
pruritis, in consequence of which the paAv had been brought 
into use, and so received contagious matter sufficient for a 
fresh establishment of the parasite. The pustule, so to 
speak, at the root of the claw presented the usual colour and 
form, and was followed by a most beautiful cup-shaped 
favous crust, thus leaving no doubt as to the affection being 
the genuine T. favosa. 
No treatment was adopted to rid either the rabbits or 
kitten from the attacks or effects of the fungous parasite which 
had thus wilfully been brought home to them, as I in¬ 
tended to destroy them in order that I might have an oppor¬ 
tunity of thoroughly acquainting myself with the nature and 
habits of the parasite. 
This concludes the necessary details as to the series of 
experiments entered upon to ascertain whether or not T. 
favosa may follow on the receipt of the contagious matter of 
T. scutulata or common ringworm in cattle; in fact, to 
settle whether or not both affections are caused by one and 
the same vegetable parasite. I will now offer a few remarks 
as to the conclusions which may be drawn from the results 
of these experiments, as well as from the data brought forward 
in my former communication. 
Whatever form the effects of the parasite may assume ex¬ 
ternally, or, in other words, whatever external symptoms 
may be present (carrying with them the title favus , scutulatus , 
or decalvans , as may happen), I think there can be little 
doubt that a close and impartial microscopical investigation 
will reveal extremely little, if any, actual difference in the 
causative fungus and its component parts and their arrange¬ 
ment. So that Avhether we style the fungus Achorion, Trico- 
phyton, or Microsporon, according to its externally apparent 
effects, the fact remains that the fungus in each case is one 
and the same vegetable parasite. 
The truth of this is demonstrated : first, by microscopic 
investigation, which shows us that any seeming difference 
that may occur is simply a change in the size or arrangement 
of the spores ; a greater or less quantity (and, perhaps, slight 
