262 Trmisactions of the Boyal Society of South Africa. 
caused by the alcohol used in fixation, are more frequently found in 
the female. 
Tegumcntary Tissues. — The cuticle (Figs. 4, 6, 7, etc.), of *S'. douglasi 
appears to thicken towards the caudal extremity. It is 2-5 fx thick at 10 fi 
1 
Fig. 4. — Central nervous system and end portion of excretory apparatus in 
a female. The intestine has been displaced towards the dorsal 
wall. Magnification : 600 diameters. 
from the anterior extremity, whilst at a short distance from the bursa of 
the male and the anus of the female it reaches the thickness of 5 ji. This- 
cuticle is striated on the whole length of the parasite, but the rings are 
relatively more frequent in the posterior region of the body. In male and 
