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XLII] tained micro filariæ (for which, under the impression that it was a new species, he suggested the name of F. bourgi), found in the tissues of the heart five adult worms. Four of these were cretified, but the fifth was alive and contained embryos similar to those in the blood. This worm he subsequently identified as a L. loa. In the following year Wurtz found mf.'diurna, in the blood of a Congolese negro suffering from sleeping sickness. On the death of the patient he made a most careful post-mortem examination, and found two adult loas in the subcutaneous connective tissue of the arm. On the dissection being continued by Penel, over thirty additional specimens, male and female, were discovered under the skin of the limbs. There are not a few instances on record in which two or more loas have been extracted from the same patient. We may, therefore, be practically certain that in nearly every instance of this kind of filariasis the infection is multiple.

There is evidence that after the death of L. loa calcification takes place, as in F. bancrofti. Pathogenesis.— As already stated, L. loa daring the period of its growth and development in man makes frequent excursions through the subdermal connective tissues. It has been noticed very frequently beneath the skin of the fingers, and it has been excised from under the skin of the back, from above the sternum, from the left breast, the lingual frænum, the loose skin of the penis, the eyelids, the conjunctiva, the anterior chamber of the eye. Ziemann says that it may wander about the scalp. The parts most frequently mentioned are the eyes, and, although the worm may have attracted more attention when in this situation, it seems as though it has a decided predilection for the eye and its neighbourhood. A patient informed me that the average rate at which a loa travelled was about an inch in two minutes. Both he and others have told me that warmth, such as in sitting before a fire, seemed to attract them to the surface of the body. As a rule, the migrations of the parasite give rise to no serious inconvenience, but they may cause prickings, itching, creeping sensations, and, occasionally, transient œdematous swellings, "Calabar swellings," in different parts of the body. When the parasite appears under the conjunctiva it may cause a considerable amount of irritation and congestion; there may be actual pain even, associated with swelling}}