8 
So far as we know a similar condition of the stomach in human 
diphtheria has not been observed. 
The lesion in the stomach of the guinea pig consists of a sharply 
defined area of congestion, hemorrhage, or ulceration, near or at the 
pyloric extremity. Occasionally the lesion extends half an inch into 
the duodenum and in a few instances the duodenum itself shows slio-ht 
injection or congestion, although the stomach remains normal. 
The first stage consists principally of a congestion, always in the 
neighborhood of the pylorus. This is best seen in guinea pigs dying- 
in about twenty-four hours as a result of overpowering doses of diph- 
theria toxine. When the guinea pig dies later, for instance on the 
second, third, or fourth day, the lesion is more advanced and consists 
of hemorrhages into the mucosa followed bv destruction of tissue 
sometimes extending into the muscularis, but in no case has perfora- 
tion been observed. 
It it interesting to know whether guinea pigs that received less than 
a lethal dose of the diphtheria poison from which they ultimately 
recovered may have had this stomach lesion. In a few instances in 
our guinea pigs which died on the twenty-second and twenty-eighth 
days with paralysis we found old blood-stained areas in the mucosa of 
the stomach in the region of the pylorus, indicating a healed area. 
The lesion is not the result of any particular diphtheria toxine, for 
we have found that it follows the use of all the various diphtheria 
toxines, some 25 in number, used in this laboratory. 
There is no relation between the source of the guinea pig and the 
effects of the diphtheria toxine, since we have found this lesion in 
guinea pigs obtained from four outside sources as well as in those 
bred in the laboratory. 
W e have examined a number of healthy guinea pigs from our stock 
in order to assure ourselves that no other cause than the diphtheria 
toxine could account for the appearances that we find in the stomachs 
of guinea pigs. 
It will be seen from the following table that when guinea pigs are 
given an injection of diphtheria toxine sufficient to kill them within 
twenty-four hours, about half the animals show this lesion. 'When 
they die on the third or fourth day, a very much larger proportion . 
of the animals show the lesion. About 75 per cent of the guinea 
pigs dying between the fourth and fifth da}~s show this lesion, but 
in guinea pigs dying later than the tenth day the relative number 
of animals showing this stomach lesion gradually diminishes. Gui- 
nea pigs dying of late paralysis practically never showed the acute 
stomach lesion. 
