ON THE NEMATODES OF THE COMMON EARTHWORM. 625 
(PL 37, fig. 8) is exceedingly short and has a narrow cavitj". 
It can he distended by means of muscular fibi-es passing to 
the body-wall. Its anterior end is surrounded by three uni- 
cellular glands, two lateral and one median dorsal. The anus 
is ventral, and appears to be a transverse slit situated at the 
base of a papilla. 
The nerve collar (PI. 37, fig. 6) surrounds the oesophagus 
between the anterior and the posterior bulb. It is inclined 
obliquely iu an antero-ventral direction. 
The excretory canals (PI. 37, fig. 6), which are difficult to see, 
pursue a sinuous course in the body-wall along either side. 
From each canal a single downward branch descends towards 
the excretory pore. Biitschli (6, pi. x, fig’. 59e) represents 
these as uniting before reaching it. The excretory pore 
is situated in a median ventral position a short distance behind 
tlie posterior oesophageal bulb. 
The female is long and narrow and. tapers gently towards 
either end. 
The tail of the female (PI. 37, fig. 7) is prolong’ed to a fine 
point. It bears a pair of short papillae, one on each side, a 
little more than a third of the distance backwards from the 
anus. They do not project from the surface of the body, 
but are continued inwards, each as a delicate fibre running 
forwai'ds towai’ds the anus. They are not always exactly 
opposite one another. 
The vulva, the reproductive aperture of the female, is placed 
slightly more than half-way along the body in a median ven- 
tral position, and has two projecting lips borderijig a trans- 
verse slit. The vagina is short. In females of the typical form 
reared on putrefying worm the paired uteri are long and dis- 
tended, and contain probably between one and two hundred 
eggs (PL 37, fig. 2). In the form fed on peptone they aie 
smaller and contain five to twelve eggs 'PL 37, fig. 3). The 
ovaries are long and retlexed dorsally, nearly reaching back to 
the vulva. The so-called “seminal receptacles,” which are 
really the oviducts, are filled with spermatozoa, the female of 
this species reproducing as a hermaphrodite. They are short. 
