75 
THE EMBRYOS OF FILARIA LOA. 
By otto V. HUFFMAN, M.D. 
{From the Laboratory of the Cincinnati Hospital, 
Cincinnati, Ohio, U.8.A.) 
(With Plate IV.) 
The embryo of Filaria loa has never been fully studied or described 
and for this reason the hypothesis put forward by Manson, that the 
Filaria diurna is the larva of Filaria loa, remains unproven. When 
Manson suggested this connection he had at hand some sketches of 
embryos which Leuckart had made and sent to him. As these sketches 
were not of sufficient aid to establish the identity of the embryos with 
the larvae found by him in the blood, and as no metamorphosis takes 
place in the larvae while circulating in the blood, it is reasonable to 
suppose that they must have been rather crude sketches. However, 
the hypothesis came to be accepted because it was well supported by 
the fact that the two worms have the same geographical distribution and 
also by the occasional discovery of both in the same host. At the same 
time that this hypothesis w'as advanced, Manson changed the name from 
Filaria sanguinis hominis major to Filaria sanguinis hominis diurna and 
said that the species was practically indistinguishable on morphological 
grounds from the well-known Filaria sanguinis hominis of Lewis 
{Filaria nocturna, Manson) i.e. Filaria bancrofti. This fact made it all 
the more necessary to observe embryos taken from an adult female 
Filaria loa before venturing to state the origin of the larvae found in 
the blood. 
Only one author has stated that Filaria loa is the adult form of the 
Filaria diurna of Manson and he had nothing new in the way of evidence 
