188 ROBERT K. S. LIM 



I have made upon its stomach are more complete than in the 

 other cases. Other animals, both adult and foetal, have, 

 however, also been investigated, and the special features of 

 some of the cells of their glands are described in Parts II and III. 



PAET I. THE GASTRIC MUCOSA OF THE CAT. 



The cats were killed both while fasting and at various 

 intervals after a meal. They were usually fed on boiled fish, 

 milk, and bread, but some were put on a meat and milk diet. 

 In all twonty-fi\e animals have been examined. 



Histological Technique. 



For microscopical purposes the animals were killed either by 

 carbon monoxide or chloroform. The stomach was then 

 examined fresh or was prepared for sections. 



For the fresh preparations a piece of the mucous membrane 

 was either scraped off and teased in Ringer or serum, or the 

 fresh tissue was frozen in a little serum and cut up with a micro- 

 tome. The fresh sections, however, gave no more information 

 than those obtained after fixation, so that this method was 

 discontinued. 



For permanent preparations the fixatives used were Zenker, 

 Altmann's fluid, osmic acid 1 per cent, and forjnol (either 

 neutral 20 per cent, or acid 10 per cent.). When Zenker or 

 formol was employed the stomach was slightly distended with 

 the fixative and suspended in the same solution for the period 

 necessary for penetration. It was then cut into suitable 

 pieces, which were either placed in gum or carried through 

 in the usual way into paraffin. For some preparations pieces 

 of fresh stomach were pinneil out on a cork and iinmersed in 

 the fixing reagent ; this was the chief method when using 

 osmic acid solutions, but a few pieces were fixed in osmic 

 without stretching. 



The stains employed were alcoholic eosin and methylene 

 lilne (16). haematoxylin and eosin, van Gieson, iron haema- 



