540 Further Studies of Gastrotoxic Serum. 



DESCRIPTION OF PLATE. 



Fig. 1. — Active Immunity to Gastrotoxic Serum. 



Upper stomach : This is the stomach of the control animal, which was injected with 

 10 c.c. gastrotoxic serum. It shows patches of necrosis of the mucous membrane. 



Lower stomach : This guinea-pig had been immunised with 10 injections of gastrotoxic 

 serum. A lethal dose (10 c.c.) of gastrotoxic serum was injected. No lesion has 

 resulted. 



Fig. 2. — Passive Immunity. 



Upper stomach : This animal received a mixture of 9 c.c. gastrotoxic serum and 6 c.c. 



protective serum. No lesion is to be seen. 

 Lower stomach : This animal received a mixture of 9 c.c. gastrotoxic serum and 6 c.c. 



normal serum. Necrotic patches are to be seen in the stomach. 



Fig. 3. — Neutralisation of the Gastric Juice by Sodium Bicarbonate. 



Upper stomach : This is the stomach of the control animal, which was injected with 

 10 c.c. gastrotoxic serum. It shows necrosis of the mucous membrane. 



Lower stomach : 14 c.c. sodium bicarbonate solution (4 per cent.) were introduced into 

 this stomach, and the animal was then injected with 10 c.c. gastrotoxic serum. 

 No lesion has resulted. 



Fig. 4. — Hyperacidity of the Gastric Juice. 



Upper stomach :| This is the stomach of the control animal, which was injected with 



10 c.c. gastrotoxic serum. It shows some necrosis of the mucous membrane. 

 Lower stomach : 27 c.c. hydrochloric acid solution (1 per cent.) were introduced into this 



stomach, and the animal was then injected with 10 c.c. gastrotoxic serum. 



Extensive necrosis of the mucous membrane has resulted, and it is much more 



marked than in the control animal. 



