Another case was observed by Dr. Mitchell at Trinidad in the person of a young negress, in whom the worm appeared at long and uncertain intervals for four or five years before he had the opportunity of seeing it. At length in 1845 Dr. Mitchell saw the worm twisted like the letter S lying motionless under the conjunctiva, midway between the edge of the cornea and the inner canthus. Extraction of the worm was deferred to enable six or seven of his medical brethren to observe so unusual an appearance, with the result that when they assembled the following morning the parasite had removed itself to deeper parts.[4] A case is also recorded by Gervais and van Beneden,[5] in which M. Lestrille succeeded in 1854 in extracting a filaria from a negress, and Dr. Guyon once more, at a meeting of the French Academy of Sciences in 1864, exhibited another filaria, which had been removed by a French naval surgeon from a negro of the Gaboon. The filaria was of unusual size, measuring fifteen centimetres. Its length was such that the whole of it could not be seen at one time below the conjunctiva, part always remaining embedded in the deeper parts of the orbit.[6] Dr. Morton[7] reports a case occurring in a negress residing at Gaboon in West Africa, in which a native woman succeeded in extracting the parasite. The worm, preserved in gin, had been sent to him by a missionary, the Rev. Dr. Nassau, in the district, who informed him that although he had been very many years in that country, and had often heard of the parasite, this was the first specimen he had been able to secure. The missionary himself appeared to be also affected with filaria, which, however, did not appear on the eye, but could, he said, occasionally be felt under the skin of the fingers, and once in the skin of the lower eyelid, from which position he attempted himself to remove it with scalpel and forceps, but he did not succeed, the worm wriggling away across his cheek. The worm that was sent to Dr. Morton measured 16 mm., but was in too badly preserved a state to permit of accurate examination. Lastly, in Dr. Davidson’s work on hygiene and diseases of warm climates (p. 962) Dr. Manson, who writes the article on filaria, reports the case of a negro who had been affected with _Filaria loa_, and in whose blood he afterwards found the _Filaria diurna_, and raises the question whether the _Filaria loa_ may not turn out to be the female parental form of the _Filaria diurna_.