Cuar. VI. DIGESTION. 119 
and butyric acids, and it was completely dissolved by 
these fluids at the ordinary temperature of a room. 
Here, then, at last, we have a case in which it appears 
that there exists an essential difference in digestive 
power between the secretion of Drosera and gastric 
juice; the difference being confined to the ferment, 
for, as we have just seen, pepsin in combination with 
acids of the acetic series acts perfectly on gluten. 
I believe that the explanation lies simply in the fact 
that gluten is too powerful a stimulant (like raw 
meat, or phosphate of lime, or even too large a piece 
of albumen), and that it injures or kills the glands 
before they have had time to pour forth a sufficient 
supply of the proper secretion. That some matter is 
absorbed from the gluten, we have clear evidence in 
the length of time during which the tentacles remain 
inflected, and in the greatly changed colour of the 
glands. 
At the suggestion of Dr. Sanderson, some gluten 
was left for 15 hrs. in weak hydrochloric acid (02 per 
cent.), in order to remove the starch. It became 
colourless, more transparent, and swollen. Small 
portions were washed and placed on five leaves, which 
were soon closely inflected, but to my surprise re- 
expanded completely in 48 hrs. A mere vestige of 
gluten was left on two of the leaves, and not a vestige 
on the other three. The viscid and acid secretion, 
which remained on the discs of the three latte: 
leaves, was scraped off and examined by my son 
under « high power; but nothing could be seen 
except a little dirt, and a good many starch grains 
which had not been dissolved by the hydrochloric 
acid. Some of the glands were rather pale. We 
thus learn that gluten, treated with weak hydro- 
chloric acid, is not so powerful or so enduring a 
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