254 
J. STEPHENSON. 
of the pharynx there run outwards to the body-wall a number 
of radially arranged bundles of muscular fibres which, when 
they contract, draw the pharynx backwards, and at the same 
time dilate it.” 
One of the constituents of this pharyngeal thickening, not 
mentioned in the ordinary descriptions of the earthworm, is 
nevertheless a prominent feature, easily visible under the 
lens in the ordinary dissection, and immediately obvious, 
owing to its staining properties, in sections through the 
region where it occurs. This constituent is a cellular mass 
which forms soft white projecting lobules on the dorsal and 
lateral aspects of the pharynx ; the lobules surround the 
muscular strands which issue from the pharynx, and in 
addition, the cells of the mass penetrate inwards between 
the interlacing muscular bundles of the thick dorsal pharyn- 
geal wall in the direction of the lumen of the canal. 
Though these cells have received some attention from 
previous writers, an adequate account of their nature and 
origin has not yet, I believe, been given. 
References to previous authors are given by Vejdovsky 
(9, 1884), from whose account of them I quote, since the 
older literature is inaccessible to me. The earlier investi- 
gators — Leo, Clarke, Lankester — who saw these masses of 
pharyngeal cells in Lumbricus, interpreted them as 
glandular. Perrier described pharyngeal glands in several 
genera; in Pontodrilus they are said to be variously coiled 
tubes whose walls are composed of large cells with granular 
contents; in Moniligaster they pour their secretion into 
the pharynx by a multitude of small canals visible with the 
lens; Perichseta houlleti has several layers of glands 
which open into the interior by three pairs of orifices. 
Claparede refers to those cells of the pharyngeal mass which 
penetrate inwards between the muscular bundles as “ . . . 
numerous polygonal cells with large round nuclei 6 fi % in 
diameter. The import of these cells is at present not clear 
to me. Their similarity to ganglion-cells is not to be denied, 
though a connection with nerves could not be recognised. 
