16 
HoGG^ on Vegetable Parasites. 
mixed with favus crusts. The disease is one commonly 
known as cupped ringworm, or honeycomb scall^ and is now 
rarely seen in this metropolis ; therefore I consider myself 
fortunate in having been able, through " the kindness of my 
friend Mr. Hunt, to investigate three cases, from each of which 
I collected scales for microscopical examination. I have 
here a few of the peculiar-looking crusts, and it will be ob- 
served that they are cupped in appearance, and of a dingy 
yellow colour. The crust is almost entirely composed of the 
Achorion, mixed with epithelial scales and broken hairs. 
When the fungus once establishes itself, so fearful are its 
ravages that in a very short space of time the whole of the 
cutaneous surface, with the exception of the palms of the 
hands and soles of the feet, becomes covered with it. I 
attempted to obtain a photograph of one of the patients, but 
cannot say very successfully ; the print gives but a faint idea 
of the disagreeable picture really presented to the sight. 
Large masses of the crusts fell off daily, each one leaving its 
mark behind. As the spores penetrate the hair-follicles they 
destroy the sheaths of the hairs, which shrivel up and lose 
their colouring matter, and then break off, leaving the sur- 
face bald. 
The fact of the surface becoming so entirely denuded is 
explained in this way : — The shaft of the hair is less in cir- 
cumference than the bulb, and consists of hardened, shrunken 
epithelial cells, almost devoid of germinal matter; and the 
further removed from the bulb the less of vital power does it 
possess, and consequently, when its nutrient supply, small 
even at first, become interfered with and lessened by the in- 
creasing spores, it loses the little vitality it ever had, dies, 
and drops off. And in this, as in other cases, the fungus 
feeds upon the dead, and not the living, material. 
If we now take a crust and examine it more closely, it will 
be seen to be made up of an outer and older part, thick and 
dark in colour, the fungus being here in a more advanced 
stage, and chiefly composed of sporangia, spores, and mycelia, 
with fragments of several hairs imbedded in them. The 
under or inner and younger layer is paler in colour, and 
consists of spores mixed with epithelium, fatty and granular 
matters, and sometimes pus ; and I suppose we may consider 
that in some cases a very large quantity of the latter ingre- 
dient (pus) has been mixed up with the outer parts of the 
crusts. Mr. Wilson started a new theory, founded on this 
exceptional condition, namely, " that the favus matter is 
produced from the development of the nuclei of pus-cells that 
the parasite is not a vegetable, or that, if it be, it might be 
