8 MR. JAMES JOHNSTONE OK THE 



the stomacli. The striated, transverse oesophageal musculature 

 is gradually replaced by the nonstriated musculature of the 

 stomach. On the pyloric side, the distribution of striated muscle 

 fibres is coterminous with that of the oesophageal epithelium. 

 On the cardiac side this double line of demarcation between 

 oesophagus aud stomach is not so clear, but exists to a large 

 extent. 



The primary gland tubules, as in the case of Pliascolomys, are 

 made up of central and parietal cells. But the tubules which in 

 the Wombat are straight and unbranched, are here more complex. 

 A single tubule (PL 1. fig. 6) is lined at its opening on the 

 surface of the stomach with columnar cells {cn.^, which ia the 

 neck are replaced by clear cubical cells. At the first bifurcation 

 the parietal cells (cp.) appear. In the tubule figured a group of 

 eight lesser tubules is brought about by a triple bifurcation. 

 Other of the glands are simpler or more complex, but this type 

 seems to be the more general. 



Each opening (o) on the surface of the gastric gland leads 

 into a relatively wide tubule which, after remaining uudivided 

 for a length equal to twice or more than twice its own diameter, 

 branches into two or more divisions, from which other branches 

 are given off, either laterally or terminally. These branches 

 end blindly ; in diameter they are about 0*5 mm. There are no 

 anastomoses. In the end a very complex cluster of short 

 tubules is produced. The course of these branch tubules is 

 generally transverse to the long axis of the stomach, so that 

 ia sections taken through the pylorus and oesophagus they 

 are mostly cut transversely. In sections in the same plane, 

 passing through the more peripheral portion of the glandular 

 thickening, where there are no openings on to the internal 

 surface of the stomach, the whole gland-pad consists of a closely 

 packed mass of these branched tubules bound together by 

 muscular and connective tissue. I have counted as many as 35 

 of them cut transversely in a section passing through the peri- 

 pheral portion of the gland. 



As might have been expected from their external form and 

 situation, the gastric glands of Phascolomys, Phascolarctus, and 

 of Castor do not exhibit any essential points of difference in their 

 minute anatomy. From Toepfer's account (11), the gland in the 



