12h DR. F. E. BEDDARD ON 
asexual form is therefore in reality a bladder-worm, and not an_ 
adult in which sexual organs have not yet appeared. 
Text-figure 7. 
S.C. 
Section through skin of the fully developed asexual worm. 
C. Cuticle. s.c. Subeuticular layer below which are the saes containing 
calcareous corpuscles. 
Furthermore, it is to my mind evident that the ** closed cavities 
of very problematical nature ” which occur in the fully-developed 
sexless worm, which it will be remembered are not segmentally 
arranged and which have a lining of cuticle and epithelial cells, 
are the cavities lettered A and C in my figure (text-fig. 2) of the 
young plerocercoids. In addition to these there are various 
tubular cavities which seem to belong to the water-vascular 
system, and which | observed to approach very closely to the 
exterior of the body but not to open thereon. ‘These tubes, 
present in addition of course to the four longitudinal trunks, are 
exactly repeated in the younger stages that have been described 
in the present communication. There is therefore no abrupt 
break between the much more bladder-worm-looking embryos 
