Filaria loa 23 



(=;F. papulosa) as occurring both in man and in the horse in 

 India. 



It is of great interest to note that in North America is found 

 a species which occurs at timec in the eye of the horse. Such 

 cases are recorded for Canada by Sermon (1872) and for Penn- 

 sylvania by TurnbuU (1878). In spite of the designation of the 

 parasite in the first case as F. ocidi, much used for F. loa by 

 medical authorities, we are justified in attributing the case to 

 some other species since the patient was a bay mare. Now the 

 occurrence in this territory of a filaria in the eye of the horse 

 necessarily casts a shadow of doubt upon cases in man in which 

 the supposed F. loa was not carefully examined since, as has 

 been noted, species of similar habit in Italy and India occur at 

 times also in the human eye. It is indeed altogether likely that 

 cases will occur in this covmtry in which the horse parasite will, 

 as an erratic, invade the eye of man. 



In view of these facts one would be justified in expressing 

 doubt as to the correctness of certain cases generally listed with 

 F. loa. In particular the cases of Lallemant (No. 18), and dos 

 Santos (No. 19), from Brazil may justly be questioned. To be 

 sure, both were originally reg"arded as cases of the Guinea worm, 

 and only by later authors have they been interpreted as F. loa 

 by virtue of their occurrence in the eye. While I am inclined 

 to regard this habit as sufficient reason for rejecting the original 

 determination, it should be confessed there is some ground for 

 doubting the assignment of the worm to the species F. loa. The 

 cases are unique in Brazil, and there is no evidence that the 

 hosts, although of negro blood, were recent importations from 

 Africa. Now while there attaches some doubt to all cases in 

 which a positive determination of the specimen was not made, 

 yet, when the history of the host shows recent importation from 

 Africa, as in many of those reported from the West Indies, the 

 uncertainty is very slight. When the case history is not so clear 

 the possibility of a chance infection with some form indigenous 

 to the region is not definitely excluded. • In other words, should 

 future- study show the presence in Brazil of some species such 

 as is F. conjunctivae in Italy, the cases so definitely assigned 



293 



