250 REPORT OF THE HARVARD AFRICAN EXPEDITION 
on the other hand, have observed larvae abundantly present in apparently 
normal skin. 
We also have found the epidermis perfectly normal as far as visible lesions 
were concerned in some cases in which large numbers of the larval forms of 
Onchocerca were present. Perhaps in certain individuals with great suscepti- 
bility to the products of metabolism of these parasites inflammatory changes 
and scratching of the skin might result. On the present Expedition, the pruritis 
or craw-craw observed in Liberia in young children was in some instances due to 
Sarcoptes scabiei and in these cases Onchocerca was not present in the skin. 
Hoeppli,! in the examination of two cases with O. volvulus tumors also concluded 
that the larval forms of Onchocerca do not usually give rise to such lesions of the 
skin as described by Ouzilleau and Laigret. 
Several observers have previously thought that elephantiasis might be pro- 
duced by Onchocerca but this view is not generally accepted. Laigret * has re- 
ported a case in which there was a volvulus cyst upon the left side of the chest 
in the axillary line. Upon puncture of this cyst, numerous microfilariae of 
O. volvulus were obtained. There was also elephantiasis of the left foot and begin- 
ning on the right foot. Both legs showed greatly dilated varicose vessels. ‘There 
was no elephantiasis of the genital organs. Upon centrifugation of the blood, 
however, microfilariae of F. perstans were also found, though in rather small 
numbers. 
Sharp ® says that the larval forms of Onchocerca are often present in hydrocele 
fluid and confirms Ouzilleau in his association of Onchocerca with cases of ele- 
phantiasis. He believes that the first sign of the disease is not a subcutaneous 
tumor but the existence of active embryos in and around the corium, and he 
believes the tumors are only late manifestations of infection. In Nigeria he 
found skin infection in fifty-five per cent but tumors only in thirty per cent. 
Robles * called attention in Guatemala to the occurrence of fibromatous 
nodules upon the scalp, usually about the size of a nut, containing filaria, that 
were associated with disturbances of the eye, particularly of vision. He em- 
phasized that these disturbances disappear following removal of the tumors, and 
illustrated his report with photographs of such cases. The cases were observed 
only in a narrow zone of territory at an altitude of 600-1200 meters. Subse- 
quently Pancheco Luna,’ Calderén,° and Azurdia ’ confirmed these investigations 
and the favorable results obtained by treatment. Brumpt * who studied patho- 
logical material furnished by Robles, described the filaria as a new species, call- 
ing it Onchocerca caecutiens. While it is almost identical with the species volvulus, 
he states that it differs especially in the size and distribution of the papillae in the 
1 Hoeppli: Beihefte, Arch. f. Schiffs-u. Tropen-Hyg. (1927), XX XI, 251. 
2 Laigret: Bull. Soc. Path. Exot. (1922), XV, 303. 
’ Sharp: Proc. Royal Soc. Med., Section Trop. Dis. and Parasit. (1927), XX, 927. 
4 Robles: Bull. Soc. Path. Exot. (1919), XII, 442. 
5 Pancheco Luna: La Juvendud Medica, Guatemala (1921), Jan.—April. 
6 Calderén: Contribucién al estudio del Filarido Onchocerca sp. Dr. Robles 1915 y de las enfer- 
medades que produce. Dissertation, Guatemala (1920). 
7 Azurdia: Intern’! Conf. on Health Problems in Trop. America, United Fruit Co. (1924), p. 256. 
8 Brumpt: Bull. Soc. Path. Exot. (1919), XII, 464. 
