260 
J. STEPHENSON. 
of the cells which lie deep among the muscular bundles of 
the pharynx is frankly unintelligible to me. The authors 
who have seen ductules and their endings in the pharyngeal 
epithelium have, I believe, been misled by preconceived ideas 
on the nature of the cells, and by the appearances due to the 
transformation of the deeper cells into connective tissue. 
Material and Methods. 
I have investigated in detail the five common species of 
earthworms found in Lahore; three of these, Pheretima 
posthuma (L. Vaill.), P. heterochseta (Mchlsn.), and 
P. hawayana (Rosa), belong to a genus of Megascolecidse ; 
two, Helodrilus (Allolobophora) caliginosus subsp. 
trapezoides (Ant. Dug.), and Helodrilus (Bimastus) 
parvus (Eisen), to the Lumbricidae. In addition to adult 
specimens, I have examined a number of younger worms of 
both families, and also several Lumbricid embryos in various 
stages, taken from the cocoons ; but only one of these latter 
gave me additional information. I am also familiar in a 
general way with the cell masses as they occur in a large 
number of other worms, which I have sectioned from time 
to time in the course of systematic work on Indian Oligo- 
chaeta ; though as I cannot answer for the histological con- 
dition of this material (which mostly formed part of the 
Indian Museum collections) I have not made use of it in the 
present account. 
The methods of fixation employed were Zenker’s fluid and 
sublimate-acetic for the embryos and smaller worms, including 
the adults of Helodrilus parvus; some specimens of 
Pheretima were also treated by one or other of these 
methods. Narcotisation with chloretone and fixation by 
10 per cent, formalin were employed for most of the adult 
specimens of Pheretima and Helodrilus caliginosus. 
For staining, the most generally useful method is some 
degree of overstaining with Delafield’s hsematoxylin, differen- 
tiation with acid alcohol, and counterstaining with alcoholic 
