432 



Dr. C. Bolton. On the 



[Jan. 25, 



The mixture is incubated, and at the end of four hours it is seen that a 

 similar precipitate has formed. The gastrotoxic serum may precipitate the 

 serum in as high a dilution as it does the proteid of the gastric cells. 

 The gastrotoxin does not therefore act exclusively upon the proteid of the 

 gastric cells. 



4. Action upon the Intact Gastric Cells. 



Method. — A guinea-pig's stomach is washed quite free from blood before 

 removal from the body, as described above. The superficial portion of the 

 mucous membrane is gently scraped off with a knife and suspended in a 

 few cubic centimetres salt solution. The test-tube is now very carefully 

 shaken up for a few seconds and allowed to stand for about 10 minutes, 

 at the expiration of which time the contents will have separated into two 

 portions : — 



1. A milky fluid. 



2. Small pieces of mucous membrane, which either float on the top of the 



fluid or settle to the bottom. 



The milky fluid is the portion used. It is pipetted off, and on microscopic 

 examination is found to contain in suspension free cells, masses of cells, and 

 fragments of glands, together with broken-up cells, free nuclei, and proto- 

 plasmic granules. 



It is quite easy to separate the cells, because on slow centrifulgalisation 

 the cells and fragments of glands sink to the bottom, but the granules and 

 nuclei remain in suspension. 



The cells are washed to clear away the granules and soluble proteid. A 

 suspension of cells, masses of cells, and fragments of glands in salt solution 

 is thus obtained. 



The free oxyntic cells are large oval structures with well-defined granules, 

 but the central cells, which are of a more delicate structure and contain finer 

 granules, tend to cling together in masses and are easily broken up if too 

 vigorous shaking is employed. 



In doing an experiment three or four drops of suspension of cells are 

 placed in 2 c.c. gastrotoxic serum in a test-tube, and the mixture incubated 

 for four or five hours. Controls are prepared with normal rabbit's serum and 

 also salt solution. 



Lysis. — The deposit which has formed in the tube is examined micro- 

 scopically. I have done a large number of these experiments, and always 

 with the same results. I have never observed either solution or 

 agglutination of the cells, such as has been described in the case of other 

 cy totoxins ; in fact, the cells in the serum are much more ■ separated than 



