markings at the cephalic end. He says that if the section of the papule be made sufficiently deep, five or six of these parasites may be seen in a field.
Craw-craw is said to be contagious. It appears after an incubation period of three days, and is not curable by sulphur inunction.
O'Neil's observations have not been confirmed. I think it is quite possible that the parasite he found was one of the several blood filariæ we now know to be so common on the West Coast of Africa. It is comprehensible that, in a country in which mf. perstans occurs in every second individual, it would be frequently found in such preparations as O'Neil examined. The removal of the top of a scabies or other papule would certainly be attended with some degree of hæmorrhage; in which case, should the patient chance to be the subject of any form of filarial infection, microfilariæ would be found in the preparation. Immersion in water would, as in the case of O'Neil's parasite, quickly kill the parasites. I do not wish to assert that O'Neil's parasite was mf. perstans, but the possibility of this must not be overlooked.
A disease resembling O'Neil's craw-craw was described some time ago by Prof. Nielly under the title dermatose parasitaire. A French lad, who had never been abroad, became affected with a papulo- vesicular itching eruption resembling scabies, in which Nielly found a filariform parasite somewhat like that discovered by O'Neil in craw-craw. It had the same peculiar cephalic markings; in addition, it had a well-defined alimentary canal and rudimentary organs of generation. Nielly found nematode embryos in the blood in this case; so that we are justified in believing that the parasite in the skin was an advanced developmental form of the embryo in the blood, and that both were the progeny of a mature parental worm living somewhere in the tissues. Possibly Nielly's dermatose parasitaire and O'Neil's craw-craw were of the same nature.
Symptoms.— The term craw-craw is very loosely applied. Emily has described under this name a
