682 
MR. J. N. LANGLEY ON THE HISTOLOGY AND 
Four equal-sized test tubes are taken; in each, is placed 15 cnb. centims. of hydrochloric acid (0'2 per 
cent.), together with 2 cub. centims. of carmine-stained fibrin swollen to a jelly by hydrochloric acid 
(02 per cent.). To these 3 cub. centims. of the filtered fluid from (1). (2), (3), and (4) respectively are 
added; in five minutes the test tubes are shaken well, and the fibrin allowed to settle. In eight minutes 
the coloration is compared with Geutzner’s scale freshly made. 
(1) tint considerably deeper than x. of scale. 
(2) = viii. 
(3) =vi. 
(4) =0. 
There is an obvious difference in the amount of fibrin undissolved in (2) and (3). 
In three-quarters of an hour the following is the state of things:— 
(1) Mere trace of fibrin nndissolved. 
(2) Small quantity fibrin undissolved. 
(3) About twice as much fibrin left as in (2). 
(4) No trace of coloration. 
This shows clearly enough the difference in pepsin-content of (3) and (4). In order to bring out more 
clearly the difference in (1), (2), and (3), a smaller quantity of the acid extract must be taken. 
3.20.—One cub. centim. of (1), (2), (3), and (4) is added respectively to four test tubes, each of which 
contains 15 cub. centims. hydrochloric acid (0’2) and 2 cub. centims. swollen carmine-stained fibrin. 
3.27.—(l)=v. 
(2) =i. 
(3) =0. 
(4) = 0. 
3.37.—(1) = vii-viii. 
(2) == iii. 
(3) = 0. 
(4) — 0. 
3.45.—(1) Nearly all fibi’in dissolved. 
(2) About half fibrin dissolved. 
(3) Small amount dissolved. 
(4) No fibrin dissolved. 
At 4.45 (4) still shows no coloration. On the next day, however, only a trace of fibrin is left. Under 
similar circumstances hydrochloric acid (0'2 per cent.) alone takes two days to produce a like effect. 
Swiecicki gives the following table (s. 450) :— 
Hana temporaria; hungry ; winter time. 
Time. 
2.35. 
2.45. 
2.50. 
2.55. 
3.0. 
GCsophagus. 
>1. 
I.-II. 
III. 
IV.-Y. 
V. 
Cardiac region ..... 
0 . 
I. 
I. 
II. 
<11. 
Pylorus. 
0 . 
0 . 
>1. 
I. 
II. 
So that in twenty-five minutes the pyloric region has dissolved very nearly as much fibrin as the cardiac 
region, and the cardiac region about half as much as the oesophagus; and yet Swiecicki concludes that 
the stomach forms no pepsin. It wall be seen that my experiments show much wider differences in the 
pepsin-content of the various portions, in great part, I think, since I have been careful to obtain each 
gland form without any admixture of the neighbouring gland forms. It is possible, too, that the winter- 
frog used by Swiecicki contained very few grannies in the oesophageal glands— i.e., that the pepsin- 
content w r as in these glands below normal. 
