PHARYNGEAL GLAND-CELLS OF EARTHWORMS. 
261 
eosin. Dobell’s modification of Heidenhain’s iron-hsematoxylin 
method ( 3 ) has also given me excellent results, and I should 
like to confirm what its author says regarding its value and 
convenience. One or other of the above methods was em- 
ployed for all specimens used in descriptions of the cells. In 
addition, I have used Heidenhain’s original chromhaematoxylin 
method, which gives unsurpassed differentiation of epithelial 
cells (skin, pharynx, oesophagus), but in my hands has been 
useless for the cells of the pharyngeal mass. Van Gieson’s 
stain, and borax-carmine followed by picroindigo-carmine, 
were useful in differentiating the connective tissue and in 
distinguishing it from the muscular fibres. 
I have to thank my friend and former pupil, L. Baini 
Prashad, M.Sc., Alfred-Patiala Research Student of the 
Punjab University, for kindly giving me the embryos and 
some of the youngest specimens used in the investigation. 
Pheretima Posthuma. 
General description. — In this species, in front of 
septum 4/5, a soft mass extends forwards almost to the 
anterior end of the body, filling up the available space, and 
hence narrower in front where the cerebral ganglion lies 
across it. The posterior end, or base of the somewhat conical 
mass, can be separated only with difficulty from septum 4/5, 
against which it lies, on account of the numerous- strands of 
muscle which issue from the mass and pass backwards 
through the septum. When the separation has been accom- 
plished, the posterior part of the mass is, seen to be composed 
of numerous micronephridial tubules the pharynx with its 
associated aggregations of “ gland-cells 39 lies in front of 
this. 
Emerging from the dorsal and lateral surfaces of the 
pharyngeal mass are numerous strands and sheets of muscle 
which take in general an obliquely backward direction ; the 
obliquity is less in front, where the strands are more nearly 
transverse in direction, and greater behind, where they are 
