98 DROSERA ROTUNDIPOUA. [Cuap. VI. 



In not one of these ten cases was the whole of the gluten 

 dissolved, even when very small bits were given. I there- 

 fore asked Dr. Burdon Sanderson to try gluten in artificial 

 digestive fluid of pepsin with hydrochloric acid; and this 

 dissolved the whole. The gluten, however, was acted on 

 much more slowly than fibrin ; the proportion dissolved with- 

 in four hours being as 40.8 of gluten to 100 of fibrin. Gluten 

 was also tried in two other digestive fluids, in which hydro- 

 chloric acid was replaced by propionic 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 pyower 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 explana- 

 tion 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 ab- 

 sorbed 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 transpar- 

 ent, 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 re- 

 mained on the discs of the three latter leaves, was scraped off 

 and examined by my son under a 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 hydrochloric acid, is not so power- 

 ful or so enduring a stimulant as fresh gluten, and docs not 

 much injure the glands; and we further learn that it can be 

 digested quickly and completely by the secretion. 



