GASTEIC GLAA^DS OF THE MABSUPIALIA. O 



10 mm. in diameter. Although it had not attained its greatest 

 development in point of size, I have no reason to suspect that its 

 anatomical details differed in any essential respects from those 

 characteristic of the gland in the fully-grown Koala. The openings 

 were much smaller than those in the Wombat, 25 in number, and 

 occupied a central portion of the glandular thickening, round 

 which was a part of the thickened area of mucous membrane free 

 from openings. Unlike Fhascolomys, the gland was situated 

 nearly midway between the oesophagus and pylorus. 



Phascolomts. 

 A section of the gland in the Wombat, taken parallel to the 

 surface of the stomach, some little distance below the surface but 

 before the bifurcation of the tubules has taken place, shows a 

 number of tubules of varying diameter and of irregular distribu- 

 tion. The area of the gland is sharply bounded by a circularly 

 running tract, which contains the cardiac glands of the surround- 

 ing epithelium of the stomach, and in which those glands are 

 cut somewhat obliquely : this appearance is due to the plane 

 of the section passing through the thickening of the gastric 

 gland and surrounding epithelium. The gland itself is a some- 

 what lenticular shaped pad, due entirely to the complex folding 

 which the mucous membrane has undergone. The surface of 

 this thickening, facing the interior of the stomach, is slightly 

 depressed. Towards the external surface the gland presents a 

 convex border. In relation to each tubule tliere is a closely 

 investing sheath of muscularis mucosae, which accompanies it in 

 its evagiuation outwards. This sheath consists mostly of a 

 layer of plain muscle fibres, running transversely in relation to 

 the long axis of the tubule, and, external to this transverse layer, of 

 a very meagre, and in many places discontinuous, sheath of fibres 

 running iu the direction of the long axis of the tubule. Between 

 these tubules is a space which is an extension of the submucosa of 

 the general gastric epithelium, and which is occupied by areolar 

 tissue containing blood vessels, lymph spaces, and muscle fibres. 

 The latter are of two kinds — bundles of plain muscle fibres 

 and of less abundant striated fibres. These are almost entirely 

 derived from the muscular coats of the stomach, but probably 

 also to some extent from the muscularis mucosae. The primary 

 tubules in the epithelium lining the evaginations which make up 

 the gland are continuous with those ni the cardiac region of the 



