Page:Tropical Diseases.djvu/790

738 Galgey found five adult female filariæ in the omental tissues of a patient in whose blood mf. demarquaii had been discovered during life. No male was found.

These worms closely resembled the adult F. ozzardi, but, according to Daniels, exhibited structural differences, especially as regards the shape of the head and tail, which led him to conclude that they are specifically distinct. They measured from 65-80 mm. in length by 0.21-0.25 mm. in breadth. The head has a diameter of from 0.09 to 0.1 mm. The mouth is terminal. The genital pore opens at 0.76 mm. from the head. The alimentary canal is nearly straight, and terminates in an anus which is subterminal. The opening of the anus is marked by a slight papilla. The tail is curved and rapidly diminishes in size just below the anal papilla. A marked cuticular thickening covers the tip of the tail. The diameter near the tip of the tail, before its termination, is 0.03 mm. F. demarquaii is a thicker worm than F. perstans. It differs from F. bancrofti and F. ozzardi in the greater size of the head, in the smaller tail, and particularly in the marked cuticular thickening at the tip of the tail. This thickening is knobby and bifid, but the divisions are not so well marked as in F. perstans. The intermediate host has not been discovered. Low believes it to be a rare species of mosquito. It is quite possible that some of the minute, sharp-tailed filariæ (F. ozzardi) of British Guiana are the same species. I have also found a minute, non-sheathed, sharp-tailed microfilaria, closely resembling mf. demarquaii, in the blood of natives of New Guinea. Whether these various minute, sharp-tailed, non-sheathed embryos belong to one or to several species it is impossible to decide until the adult forms of each have been discovered and carefully compared.

Some years ago I received from Dr. Ozzard, British Guiana, a number of blood films prepared from aboriginal Carib Indians inhabiting the back-country of that colony. Although the negroes and other inhabitants of the littoral and settled districts of British Guiana are very subject to F. bancrofti and to elephantiasis, in none of the considerable number of slides of Carib blood from time to time received from Drs. Ozzard and Daniels have I once encountered mf. bancrofti. Daniels records an identical experience. I am assured by Dr. Ozzard that elephantiasis is unknown amongst these people. On examining the blood slides referred to, I discovered certain nematode larvae with characters so peculiar that I suspected they represented at least one new species of blood worm, which I called, provisionally, F. ozzardi. At least half the slides examined contained these parasites, some slides only one or two, other slides as many as forty or fifty. In size and shape five out of six of the embryos resembled very closely mf. perstans (p. 735)— that is to say, they were blunt-tailed, had no sheath, and were very minute (0.173 to