36 D. KEILIN 
exist probably in all earthworms, form a salivary gland which 
pours its secretion into the pharynx. This has been denied, 
however, by Stephenson, in a paper specially devoted to this 
subject. 
After a careful critical examination of the work of all the 
previous authors, Stephenson writes (loc. cit., p. 260): ‘ The 
authors who have seen ductules and their ending inthe pharyn- 
geal epithelium have, I believe, been misled by preconceived 
ideas due to the transformation of the deeper cells into connec- 
tive tissue.’ Karlier (p. 259) he says: ‘ It willsave repetition to 
state that in none of my sections, which were taken in all the 
three planes, have I seen structures that could be interpreted as 
ductules.’ 
He passes then to the description of these cells and their 
eradual transformation into the ‘ fibrillar or reticular packing 
tissue (‘‘ Fiillegewebe’’) between the muscles’ in several species 
of earthworms belonging to the genera Pheretima and 
Helodrilus (Allolobophora). His study is concluded 
by the following statements: ‘The “ pharyngeal gland-cells” 
of earthworms are not gland-cells in the usual sense, and do not 
communicate with the pharynx ; the term “chromophile cells ”’ 
is proposed for them because of their intense coloration by 
haematoxylin and similar stains. The so-called “septal glands’ 
of earthworms are aggregations of similar cells at a more poste- 
rior level.’ . . . ‘ While most of the cells form a more or less 
compact aggregate on the surface of the pharyngeal mass, a 
number penetrate inwards towards the pharyngeal epithelium, 
and become progressively metamorphosed into fibrillar con- 
nective tissue.’ 
As to the function of the chromophile cells, he writes (p. 281) : 
‘Though in the light of what has gone before we may reject 
the usual supposition that the cells pour a secretion mto the 
pharynx (or oesophagus, in the case of the smaller more 
posteriorly-situated aggregates), it is not easy to propose 
another hypothesis to take its place’... ‘That the main 
function of the cells is metabolic is, though only a vague state- 
ment, perhaps as far as we are justified in going.’ 
