C. H. Treadgold 
133 
Taking the known facts into consideration, it would seem as though the 
production of an efficient anti-Zoa serum were possible. The subject requires 
investigation. 
SUMMARY. 
Papio cynocephalus from French Guinea frequently harbours Loa papionis 
n.sp. The intermediate host is unknown. The larvae, in contradistinction to 
those of the human parasite Loa loa, show no diurnal periodicity. 
The occurrence of bacterial disease in adult L. papionis would seem to be 
a novelty; at any rate I could find no mention of diseased filariae in the 
literature. 
In so far as the biology of Microloa loa is concerned, I am inclined to doubt 
the correctness of the opinions expressed by Roden wait and Fiilleborn con¬ 
cerning the structures they term “executory and genital cells”: the current 
hypotheses concerning the significance of these structures and of the “ central 
viscus,” clearly need revision. Manson’s “buccal apparatus” would seem to 
be nothing more than an optical illusion, while the “neck” or “shoulder” 
described by the older observers as existing in adult L. loa after fixation, was 
evidently due to imperfect technique. 
I have drawn attention to the desirability of standardising the technicalities 
which are such essential preliminaries to the accurate mensuration of micro¬ 
filariae, and have suggested a method which has certain advantages over those 
at present in use. 
Concerning the pathology of Loa infection, evidence both of the traumatic 
and toxic action of L. papionis on baboons, was obtained; moreover these 
parasites seemed definitely toxic for guineapigs, although the single experi¬ 
ment performed needs confirmation. The available evidence favours the 
supposition that adult baboons from an infected area possess a high degree 
of immunity both against L. papionis toxaemia and against reinfection by 
these parasites; but whether their serum is of therapeutic value for human 
beings infected with L. loa, requires further investigation. 
REFERENCES. 
Annet, Dutton and Elliot (1901). Report of the Malaria Expedition to Nigeria. Part II, 
Filariasis. Liverpool. 
Blanchard, R. (1899). Nouveau cas de Filaria loa. Arch, de Parasitol. n. 504. 
Brumpt, E. (1913). Precis de Parasitologic. Paris. 
Brunetiere (1913). La filaire de l’ceil ( F. loa), peut-elle determiner les complications 
c£r6brales? Gaz. Hebdom. des Sci. Med,, de Bordeaux, July 27. 
Fantham, Stephens and Theobald (1916). The Animal Parasites of Man. London. 
Foley, F. (1913). fitudes morphoiogiques sur les microfilaires a gaine. Ann. Inst. Pasteur, 
xxvii. 50. 
Fulleborn, F. (1913). Beitrage zur Morphologie und Differentialdiagnose der Mikro- 
filarien. Arch. f. Schiffs- u. Tropenhyg. xvii. Beih. 1. 
- (1914). Zur Technik der Mikrofilarienfarbung. Centralbl. f. Bakt. etc. lxxiii. 
Heft 6. 
