70 James Francis Agsorr, The Morphology of Coeloplana. 
established by the breaking away of the margin of the cell to form the 
cup. The nucleoli are disappearing. 
Fig. 32. A strand of endothelium of a gastric canal of C. willeyi; 
budding off cells into the circulating stream. 900:1. a) cells just divided, 
b) one just separating from the strand. 
Fig. 33. Flagellate epithelium of the floor of the pharynx. 800:1. 
gl.c a gland cell in Stage C, — the greater part of the granules have 
apparently been thrown out — the nucleus is ‘visible and apparently 
Stage A is beginning in the lower part of the cell. / lacunae between 
cells due to shrinkage in fixation. 
Fig. 34. Horizontal section through root of tentacle muscle and 
accessory sheathes at sides, ©. willeyi. 80:1. g. can lumen of branches 
of gastric canal system (tentacular canal) running into the root of the 
tentacle from the infundibulum, ern endothelial lining of canal system, m. / 
formative layer of undifferentiated cells from which both muscle and 
colloblasts arise (in this region largely muscle cells), m.¢ packing of 
muscle cells about the sheath, /en muscle of the tentacle proper. 
Fig. 35. A portion of Fig. 34 (X) more highly magnified. 900: 1. 
en endothelial lining of canal system, »m. c muscle cells converging to form 
a fiber (m/f) of the tentacle. 
Fig. 36. Epithelial cells of the dorsal surface. 360:1. «a gland of 
doubtful nature possibly similar to the “albumin cell’’ described by others. 
The other two are typical gland cells in Stage C. D one discharging its 
contents, y granules passing to the exterior. 6 
Fig. 37. Transsection of secondary tentacle of C. willeyi. 95:1. 
Most of the colloblasts are torn off. 7. m inner layer of longitudinal 
muscles of tentacle (cf. Fig. 4). 
Fig. 38. Transsection (thick) of secondary tentacle of C. mitsukuri. 
300 : 1. col colloblasts, o.c. m outer layer of circular muscle in which 
the filaments of the colloblasts are inserted, 7. ¢. m inner circular layer, 
o. m outer longitudinal muscle strands, 7. m inner longitudinal muscle 
strand. 
Fig. 39. Strands of endothelium budding off cells into the canal 
system. 900:1. s septum between two adjacent canals, @ typical cell 
with central large nucleus surrounded by clear space, b suggests the origin 
of such a cell in the fusion of several smaller ones. 
Fig. 40. Flagellate epithelium of stomodaeal canal. (. willeyi. 
800: 1. 
