115 
C. H. Treadgold 
at a point between 3 and 4 mm. behind the anterior extremity; this is main¬ 
tained for a short though variable distance, after whicli the diameter gradually 
diminishes to the rounded posterior extremity. The breadth at the level of 
the anus is from 0*09 to 0-13 mm. in the <?, 0*17 to 0-21 mm. in the 
The figures recorded by Penel (1904), who found 34 L. loa at the autopsy 
of a negro, are of interest in this connection, and the differences between his 
observations and my own are brought out in Table I. In L. papionis, both 
sexes are considerably thicker and the females considerably longer than in 
L. loa; the smallest female measured by me was as long as the largest of 
Penel’s specimens, while its maximum diameter was greater. On comparing 
worms of average size with one of Penel’s—a female which forms part of the 
collection belonging to the Laboratory of Parasitology, Paris—these differ¬ 
ences appeared very obvious. 
Table I. 
Summary of chief differences between Loa loa and L. papionis. 
(For differences in the spicules, see text , p. 119.) 
L. loa (Penel’s figures, 1904) 
L. papionis 
I. The adults. 
External measurements in mm. 
c?_ 
Length Maximum breadth 
25-34 0-273-0-43 
27-33 0-4 -0-5 
$ 
Length Maximum breadth 
45-63 0-38-0-49 
63-83 0-55-0-7 
Maximum thickness of cuticle in microns. 
d $ 
L. loa Looss (1904) 9-12 9-12 
L. papionis 10-12 16-20 
Breadth of lateral bands in microns. 
Breadth of lateral band at 
base of cephalic cone 
L. loa (Looss’s figures, 1904) 
{<$ 
\9 
9 
9 
L. papionis 
js 20-35 
{2 40-60 
Breadth a short 
distance behind base 
10-15 
20-34 
Breadth at termination 
of oesophagus 
63 
90 
50-60 
80-100 
Microloa loa 
Sheath 
Measurements in microns ... 
(Fresh material) 
Shape ... ... ... 
Subcuticular cells ... 
Central viscus 
Periodicity ... 
II. The larvae. 
Present 
210-280 x 7-7-5 Low (1911) 
Numerous ... 
Seldom seen 
Diurnal 
Microloa papionis 
Usually absent 
270-330 x 6-5-7 
Posterior extremity rather more 
pointed 
Scanty 
Frequently present 
No diurnal periodicity 
