The next case recorded is one by M. Mongin, a surgeon at St. Domingo, in the ‘Journal de Médecine’ for 1770, occurring in a negress who had for twenty-four hours complained of severe pain in the eye with scarcely any inflammation. At first glance he saw a worm, which appeared to him to wriggle over the globe, but on trying to seize it with forceps he found it to be between the conjunctiva and sclerotic. To remove it he incised the conjunctiva, and it emerged through the opening. It was one and a half inches long, and the thickness of a violin string, and of an ashy colour. It was larger at one end than at the other, and very pointed at the two extremities. He was inclined to view it as a worm of the blood (_ver sanguin_), as it did not appear to him possible for it otherwise to get into that position without giving rise to pain and inflammation at the part. We have next several cases that were carefully observed and recorded by M. Guyot, a French surgeon,[2] who had made many voyages to the Angola coast of West Africa. The first case in which he discovered the filaria was that of a negress in whom, after several examinations, he noticed a ridge of the conjunctiva resembling a varicose vein, which induced him to make minute openings over it to empty it. On pricking the elevated conjunctiva with the point of a lancet he was surprised to observe the projection disappear. The patient at the same time stated that she felt something move in her eye, and that the movement was deep-seated. He suspected that this could be nothing else than a roving worm (_ver ambulant_), which sometimes appeared under the conjunctiva, sometimes dived into the posterior parts of the eye. From inquiry he found that a worm in the eye was common enough among natives of that land, and that it was called a “loa,” and he consequently applied the term filaria loa to the affection. He saw the worm on many occasions in the eye of the negress, but whenever he touched the spot where it was it retreated to the posterior parts of the orbit. On that voyage he saw several negroes with this affection, for which he employed various collyria without effect. In 1777 he made another voyage to the coast of Angola. Having many negroes on board the ship he renewed his researches, and found several individuals affected with the disease. As no benefit had been derived from the applications he had previously used he proposed to extract the worm through a small opening in the conjunctiva. To effect this it was necessary to fix the worm, to which end he employed dissecting forceps, without, however, being able to seize it.