PHARYNGEAL GLAND-CELLS OF EARTHWORMS. 
267 
nuclei become smaller; the nucleoli also diminish in size ; 
and when the deeply staining substance has altogether dis- 
appeared the nuclei (or some of them) seem to disappear 
also, becoming fainter and less easily distinguishable ; so that 
ultimately tracts of connective-tissue of some little size — at 
least as large as several of the original cells — show no nuclei 
at all. 
The Capsule. — The lobes are surrounded by a capsule, 
which consists of a thin membranous sheet with not infre- 
quent oval nuclei. This constitutes a very definite peritoneal 
covering over the posteriorly projecting lobules ; over the 
more anterior masses it is less evident. But even there it 
can be made out in places by means of the somewhat 
flattened nuclei contained within a lightly staining material, 
which fills up little inequalities in the surface or forms small 
projections. In other parts however no capsule is discover- 
able ; the limit of the mass is the limit of the chromophil 
cells themselves ; and, as owing to the disintegration of the 
periphery of the cells this is not always sharply defined, it 
would be easy in such places to distinguish a limiting 
membrane if one were present (PI. 19, fig. 4). A definite 
peritoneal investment covers the muscular strands which 
issue from the pharyngeal mass. 
Pheretima hawayana. 
General description. — The condition is not unlike that 
of the last species (PJ. 19, fig. 1). The pharynx is covered 
by a soft white mass, from which muscle bands emerge. 
Projecting behind the pharynx, and therefore in segment V, 
there are on each side two lobes, one above the other. The 
upper lobe has a smooth surface, and three muscular bands 
emerge from its posterior border; the lower is larger, 
triangular in shape with its apex backwards, smooth for the 
greater part, but the posterior tapering portion consists of 
follicles of the “ blood-glands ” clustering round a muscle 
strand. Other strands also emerge from this lobe ; and on 
