44 Henry B. Ward 



the path the worm has followed, if not immediately coincident 

 in time with its movements. There is one record of such move- 

 ment of the swelling, given by Milroy in the present paper (p. 

 47), but another similar observation has not been noted, and 

 there is nuich indirect evidence to show that it does not occur 

 ordinarily at least. In fact, these swellings are usually described 

 as oval, circumscribed, and of relatively small size; hence the 

 stimulating factor must be a variable or occasional one. Fur- 

 thermore, the swellings are single or rare, while it is indisputable 

 that the migrations of the worm are constant and considerable. 

 Its activity and freedom of movement have been commented 

 upon by many observers, and are manifest both in the eye and 

 elsewhere in the body. This striking contrast between the path- 

 ological conditions and the parasite supposed on good grounds 

 to produce them can only be explained by the assumption that 

 the exciting factor is an intermittent element in the biology of 

 the parasite, of relatively infrequent occurrence. In further 

 support of the view that the pathological condition is not the 

 result of the mere movements of the parasite may be urged the 

 record of observations concerning its movements under the con- 

 junctiva. The unanimous testimony of observers is that the 

 parasite produces no change whatever in the appearance of the 

 organ, as it moves across the surface of the eyeball, nor is any 

 alteration visible subsequently save an insignificant elevation of 

 the surface. Similarly, it has been seen -moving under the skin 

 in other parts of the body without pathological changes result- 

 ing. Important additions to the previous records on this point 

 are found in the observations of Friend, Starr, and Loveland 

 included in the preceding pages. 



Alanson reports the statement of one of his patients that the 

 erythema and swelling are due to mechanical excitation when 

 the region of the parasite is rubbed. Indeed, this lady, long resi- 

 dent in Old Calabar, informed him that if rubbing or scratching 

 is not indulged in when a Loa approaches the surface there will 

 be no swelling. It is difficult to see how the rubbing could pro- 

 duce such definite areas or how the number and frequence of the 

 swcllinirs could be so limited. Furthermore. Milrov records the 



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