but not their exterior tentacles; and so it was with all six leaves after 24 hrs.  Two days afterwards 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 decoction strongly excites the glands on the disc, causing the blade to be quickly and greatly inflected; but that the stimulus, differently 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 druggist) was dissolved in 437 of water, and drops were placed on six leaves.  Next day all six were somewhat 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 precipitated in the preparation of these drugs, I cannot doubt that some is occasionally retained; and a trace would be sufficient to excite the more sensitive leaves of Drosera. [page 85]

CHAPTER VI.

THE DIGESTIVE POWER OF THE SECRETION OF DROSERA.

The secretion rendered acid by the direct and indirect excitement of the glands—­Nature of the acid—­Digestible substances—­Albumen, its digestion arrested by alkalies, recommences by the addition of an acid—­Meat—­Fibrin—­Syntonin—­Areolar tissue—­Cartilage—­Fibro-cartilage—­ Bone—­Enamel and dentine—­Phosphate of lime—­Fibrous basis of bone—­Gelatine—­Chondrin—­ Milk, casein and cheese—­Gluten—­Legumin
—­Pollen—­Globulin—­Haematin—­Indigestible substances—­Epidermic productions—­Fibro-elastic tissue—­Mucin—­Pepsin—­Urea—­Chitine—­ Cellulose—­Gun-cotton—­Chlorophyll—­Fat and oil—­Starch—­Action of the secretion on living seeds—­Summary and concluding remarks.

As we have seen that nitrogenous fluids act very differently on the leaves of Drosera from non-nitrogenous fluids, and as the leaves remain clasped for a much longer time over various organic bodies than over inorganic bodies, such as bits of glass, cinder, wood, &c., it becomes an interesting inquiry, whether they can only absorb matter already in solution, or render it soluble,—­that is, have the power of digestion.  We shall immediately see that they certainly have this power, and that they act on albuminous compounds in exactly the same manner as does the gastric juice of mammals; the digested matter being afterwards absorbed.  This fact, which will be clearly proved, is a wonderful one in the physiology of plants.  I must here state that I have been aided throughout all my later experiments by many valuable suggestions and assistance given me with the greatest kindness by Dr. Burdon Sanderson. [page 86]