A. 0. Parsons 
363 
The Anatomy of Filaria volvulus. 
The mature worms are delicate cylindrical organisms of a greyish 
white colour, and are always found in a coiled up condition. They 
possess a thick and rigid cuticle which is annulated for the greater 
part of the body and is only seen broken in a transverse direction. 
The male worm measures from 20—32 mm. in length, and '2 mm. in 
diameter at its widest part. The female is both longer and thicker 
than the male, about twice as long, and measures 3 mm. in its thickest 
part. 
The alimentary system is represented anteriorly by a mouth that 
opens at the bottom of a very small cup-like depression having a 
cuticular lining continuous with the cuticle of the body. There are no 
circumoral papillae. The oesophagus is a stout tube possessing a 
cuticular lining and measuring '8 mm. in length. The rest of the 
alimentary canal is a thin walled straight and narrow tube filled with 
opaque matter, which seems to show that the animal feeds on organised 
tissues, and does not wholly depend on lymph. 
The male worm is hair like in form and maintains the same 
diameter throughout the greater part of its length. A very character¬ 
istic feature of the male is the single spiral twist at the end of the tail 
which is seen in all specimens. With care the male worm can be 
disentangled completely from the tumour and we found that the 
shortest worm measured 20 mm. while the longest was 32 mm. The 
cuticle is very finely ringed and resistant. The tail measures 0'07 mm. 
and ends in a bulbous blunt portion. 
Ftilleborn (1908) states that the tip of the tail is inverted to make 
a gutter like depression, but it is probable that this sulcus is apparent 
only, and is produced as a result of the arrangement of the caudal 
papillae. At 0 07 mm. from the head, the body of the male worm narrows 
to form a slightly narrower neck which is 0‘05 mm. in diameter; there¬ 
after the diameter increases uniformly until about the middle of the 
body the greatest width of 2 mm. is reached. Two groups of paired 
papillae occur at the posterior end of the worm:—(a) those near the 
anogenital pore or cloaca, and ( h ) those near the tip of the tail. 
Concerning the number and arrangement of these papillae there is 
much diversity of opinion among the various authors, but our conclusions 
are based upon an examination of several specimens and are as follows. 
