56 D. KEILIN 
the latter and the oesophageal lumen. It is very easy to con- 
ceive that a violent contraction of the earthworm will expel 
these cells, with their contents, into the lumen of the alimentary 
TEXT-FIG. 6. 
A. phd. 
ee, ; 
= pia Us Sul 
A. Schematic figure representing a transverse section of the 
pharynx of the earthworm : ph. d. = dorsal or salivary chamber of 
pharynx; ph.f.=lateral folds of the pharyngeal wall; ph. v. = 
ventral chamber of pharynx. 
Band ©. Sections of the oesophageal wall of All. foetida, 
showing a yellow cell or excretory amoebocyte in the act of 
traversing it. x 500. ae.=amoebocyte ; cu. = cuticle of oesopha- 
geal epithelium ; ¢.=oesophageal epithelium ; 0.=opening in 
the oesophageal wall through which the amoebocyte will pass 
into the lumen of the alimentary canal. ; 
canal. The fact that these excretory cells are found indif- 
ferently in all the portions of the alimentary canal corroborates 
the supposition of Willem and Minne, that these cells do not 
