PHARYNGEAL GLAND-CELLS OF EARTHWORMS. 
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spherical nuclei, or in places already flattened with elongated 
nuclei. 
The characters of the nucleus, and to some extent those 
of the cytoplasm of these cells, resemble those of the 
chromophil cells of the adult ; and it seems probable that we 
have here the first appearance of the characteristic cells of 
the pharyngeal mass. If so, they are evidently of mesoblastic 
origin, and make their appearance at the periphery of the 
pharyngeal mass. 
Function of the Cells. 
Though in the light of what has gone before we may 
reject the usual supposition, that the cells pour a secretion 
into the pharynx (or oesophagus, in the case of the smaller, 
more posteriorly situated aggregates), it is not easj> to propose 
another hypothesis to take its place. 
That some of the chromophil cells on the dorsum of the 
pharynx wander deeply into the pharyngeal mass in certain 
species and there give rise to a fibrillar connective tissue, 
seems plain. But this is obviously not the main function of 
the cells ; nor does this change occur in the smaller, more 
posterior aggregates. 
That the main function of the cells is metabolic is, though 
only a vague statement, perhaps as far as we are justified 
in going. In this connection the following considerations 
may be brought forward : 
(a) Independently of the connective tissue change, the 
cells are frequently, or usually in the adult, seen to have 
indefinite outlines, and their margins appear to be dis- 
integrating. This is visible even at the surface of the mass, 
in the cells which border the coelomic cavity. 
(b) The linear interspaces between the cells, always a 
marked feature, evidently allow of the easy percolation of the 
body fluids throughout the whole. Add to this the fact that 
the peritoneal capsule is never complete, and often (and 
especially in young specimens) largely absent, and we have the 
