50 THOMPSON YATES LABORATORIES REPORT 
worms found were sexually mature. No examination of the blood had been made. 
The worms were cylindrical, capillary, and opalescent, white, uniform in thickness 
except where the body tapered towards the tail and at the club-shaped oral end ; the 
swollen oesophagus was well marked off from the intestine. The mouth was simple, 
circular and unarmed, the cuticle marked with fine transverse striations. The female 
measured 15-5 mm. long by o-~j thick, the male 8*3 mm. long by 0*4 mm. thick. The 
vulva was 2-56 mm. from the head end, at a point which divided the length of the 
worm in the proportion of 1 : 59. The tale of the male possessed four pairs of pre- 
anal and four pairs of post-anal papillae and two spicules, 0*17 mm. long. The tail 
made one and a half to two spirals. Nothing is known of its life history. 
Filaria loa. Guyot 
This worm varies from 1 6 to 70 mm. in length, average 30 to 40. 
The female of our collection measures 50' 8 mm. in length, 0*57 mm. in 
breadth. _ q ^ 
Cobb's formula : — ' 5 °? 99 
— , — — 1 'i, 0.39 
Description. The worm is of uniform thickness throughout the whole of its 
length, except at the head end where it sharply tapers, and at the tail where for 
some distance in front of its extremity, the worm gradually tapers to less than half 
its breadth. The cuticle bears a large number of small rounded bosses apparently 
irregularly arranged as also described by Manson 1 and others. The head end has 
the shape of a cone, with an abruptly flattened apex, at the centre of which is the 
small oral orifice : no buccal appendages are apparent. The specimen is too opaque 
for the oesophagus and its junction with the intestine to be made out. The vagina 
opens at a distance of 2*5 mm. from the anterior extremity. The tail end which 
tapers considerably, terminates in a short incurved portion (in our preserved specimen), 
on the concavity of which at a distance of o - 2 mm. from the extreme tip is seen the 
anal orifice at the summit of a low broad papilla. At the extreme end are two small 
fine tubercles. The ova, containing embryos, measure 35 m by 25 m; the embryos 
measure 210/x long. 
Descriptions of two male specimens are given by Manson. 1 'Length, 25 
to 30 mm., breadth, 0-30 mm. Thickness uniform except where it tapers at the 
head and tail. Mouth simple, no papillae nor armature. The tail end is sharply 
incurved and perhaps excavated ventrally ; it is not spirally twisted. The tail is 
provided with well marked lateral alae. There are four well marked papillae on each 
side of the ventral surface of the tail. The three anterior papillae are pre-anal and 
large. They are closely approximated, stout and bulbous at the free end. The 
fourth is ad-anal or post-anal and is distinctly nearer the middle line and considerably 
I. Manson, Transactions of Ophthal. Soc. London, 1895. Case of Filaria loa, by D. Argyll Robertson. 
Charles, Set. Mem. Medic. Officers, Army of India ; vol. vii., 1892, p. 51. Argyll Robertson, Transactions of the Ophthalmological 
Society. London, 1895. Case of Filaria loa. 
