562 
THOMPSON YATES LABORATORIES REPORT 
proceeding, and a doctor might be advised to try on himself before he subjects his 
patients to it. Refractory follicles may be touched with strong iodine tincture. 
Corrosive sublimate has the disadvantage of being unpleasantly poisonous to 
leave about in lay hands for promiscuous application, so that some less dangerous 
material or form of the material would be advisable for practical purposes. As a 
suggestion, which gives promise of being well worthy of trial, I may mention the anti- 
septic soaps which are used for obstetric and other purposes, or more precisely those 
which contain mercurial salts (generally the iodide, 1 believe). A cake of such a soap 
would not be so objectionable on the score of its poisonous properties. Naturally, 
for portability, a cake of soap does not compare with a few tabloids of Hydrarg. 
perchlor : a small portion of one of which will do a good deal. Enquiry may reveal 
some more preferable protoplasmic poison ; formalin and salts of copper were not tried. 
It is not without interest to observe that the ordinary suppurating follicle with 
staphylococci is readily cut short, with carbolic acid (e.g., sat. sol.), whilst the prickly 
heat is not affected as would be probable if the skin staphylococci were the cause. 
Summary. The condition of ' Prickly Heat ' studied is infectious by contact ; 
it is associated with the presence of active amoeboid bodies ; it is curable by means 
of applications of corrosive sublimate, and, probably, other protoplasmic poisons. 
B. Drepanidium in the Toad 
All the smaller toads which we examined at Para (i.e., about the size of the 
ordinary English toad) were found infested with a species of Drepanidium. Two 
main forms of blood parasite were found, in the red-blood corpuscles one correspond- 
ing to the ordinary drepanidium and the other to Labbe's Dactylosoma. The former 
seemed to multiply chiefly, if not solely, in the internal organs (liver), the latter inside 
the circulating red-blood corpuscle. Once inside a red-blood corpuscle, it appeared 
that the drepanidium form did not leave it within the body of the toad ; for by fixing 
large quantities of blood from the heart immediately with sublimated saline solution 
and centrifugalizing we never succeeded in discovering free drepanidia ; on the other 
hand, if the blood was examined without a fixative agent or centrifugalized with plain 
citrated saline, after a short while no endocorpuscular drepanidia could be found, all 
having become free. This is suggestive that the drepanidium may be destined for a 
life in a second host. This host is, in all probability, to be found in the ticks (Ixodes). 
with which almost all the toads found were infested. Examination of the contents of 
the ticks shewed curious cysts, evidently different from the curious nuclei of the tick's 
economy, varying in size up to about 60^. It was noted that the movements of 
free drepanidia in the fluids from the tick's stomach were much more active than 
in the toad's blood ; appearances suggestive of conjugation were also seen. Owing 
to our yellow fever work the observations were necessarily fragmentary ; moreover, 
