84 DEOSERA EOTUNDIFOLIA. Chap. V. 



fact that water at this temperature extracts matter from them 

 which excites Drosera to an extraordinary degree. 



Grasses contain far less nitrogenous matter than do peas or 

 cabbages. The leaves and stalks of three common kinds were 

 chopped and boiled for some time in distilled water. Drops 

 of this decoction (after having stood for 24 hi's.) were placed 

 on six leaves, and acted in a rather peculiar manner, of which 

 other instances will be given in the seventh chapter on the 

 salts of ammonia. After 2 hrs. 30 m. four of the leaves had 

 their blades greatly inflected, but not their exterior tentacles ; 

 and so it was with all six leaves after 24 hrs. Two days after- 

 wards the blades, as well as the few submarginal tentacles which 

 had been inflected, all re-expanded ; and much of the fluid on 

 their discs was by this time absorbed. It appears that the de- 

 coction strongly excites the glands on the disc, causing the blade 

 to be quickly and greatly inflected ; but that the stimulus, dif- 

 ferently from what occurs in ordinary cases, does not spread, or 

 only in a feeble degree, to the exterior tentacles. 



I may here add that one part of the extract of belladonna 

 (procured from a di-uggist) was dissolved in 437 of water, and 

 drops were placed on six leaves. Next day all six were some- 

 what inflected, and after 48 hrs. were completely re-expanded. 

 It was not the included atropine which produced this effect, for 

 I subsequently ascertained that it is quite powerless. I also 

 procured some extract of hyoscyamus from three shops, and 

 made infusions of the same strength as before. Of these three 

 infusions, only one acted on some of the leaves, which were 

 tried. Though druggists believe that all the albumen is pre- 

 cipitated in the preparation of these di'ugs, I cannot doubt that 

 some is occasionally retained ; and a trace would be sufficient 

 to excite the more sensitive leaves of Drosera. 



