Oe 
Oo 
ba | 
bulb, which bulges prominently into the coelomic cavity. 
oe 
~ 
. 
On the Pharyngeal or Salivary Gland of the 
Earthworm. 
By 
D. Keilin, Se.D. 
Beit Memorial Research Fellow. 
From the Quick Laboratory, University of Cambridge.) 
y A § 
With Plate 3 and 7 Text-figures. 
CONTENTS. 
PREvious WoRK ON THE PHARYNGEAL BULB. 
MATERIAL AND METHops 
THE STRUCTURE OF THE PHARYNGEAL OR Sines Bue 
(a) Deep or glandular portion : 
(b) Conductive or musculo-vascular portion 
(c) Superficial or epithelial portion 
(d) Septal glands : 
FUNCTION OF THE ean cn a ae Gere 
SUMMARY AND CONCLUSIONS . 
SUPPLEMENTARY NOTES ON: 
(a) Bacteroid, or uric acid cells 
(b) Yellow cells of the alimentary canal . 
(c) Reserve substance in Oligochaetes 
REFERENCES : 
EXPLANATION OF PLATE 
1. Previous Work oN THE PHARYNGEAL BULB 
Ir is well known that the dorsal wall of the pharynx in all 
earthworms is much thickened, and forms a real pharyngeal 
By 
dissection from the dorsal surface of the earthworm, this pharyn- 
geal bulb can be easily seen with an ordinary lens and, in the 
NO. 257 D 
