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EXPLANATION OF FIGUEES. 
FIG. 
I. Dorsal view of the alimentary canal of Spurilla neapolitana ; A = mouth ; 
B = pharynx ; C = crop ; D = Salivary gland of left side ; E = mouth gland 
of same side. From a dissection. 
II. Cross-section of a piece of the mouth gland of Spurilla. 1 = lumen of tube ; 
2 = secretory cell with nucleus 3 ; 4 = nucleus of connective tissue envelope ; 
5 = muscle layer with a nucleus ; 6 all the sections are stained with iron- 
haematoxylin. 
III. Cross-section of mouth gland of Facelina Drummondii. 1 and 2 are cells before (?) 
secretory activity ; 3 are nuclei of cells after (?) prolonged activity ; 4 = tube 
with nuclei in wall ; 5 and 6 parts of neighbouring receptaculum seminis. 
IV. Cross-section of same as Fig. III. The cells are here shown in full function. 
V. Same as III. and IV. but is taken where no secretory cells are attached. 1 and 2 
muscle cells ; 3 and 4 nuclei of wall cells of tube ; 5 lumen of tube with 
secretion. 
VI. Section of mouth gland of Doto fragUis. 1 = connective tissue nuclei ; 2 = nucleus 
of excretory cell ; 3 wall of alveoli ; 4 = peripheral striated layer of secretory 
cell ; 5 = perinuclear striated layer. 
