Insectivorous Plants

[page iv.] [page v.] CONTENTS. CHAPTER I. DROSERA ROTUNDIFOLIA, OR THE COMMON SUN-DEW. Number of insects captured--Description of the leaves and their appendages or tentacles-- Preliminary sketch of the action of the various parts, and of the manner in which insects are captured--Duration of the inflection of the tentacles--Nature of the secretion--Manner in which insects are carried to the centre of the leaf--Evidence that the glands have the power of absorption--Small size of the roots...Pages 1-18 CHAPTER II. THE MOVEMENTS OF THE TENTACLES FROM THE CONTACT OF SOLID BODIES. Inflection of the exterior tentacles owing to the glands of the disc being excited by repeated touches, or by objects left in contact with them--Difference in the action of bodies yielding and not yielding soluble nitrogenous matter--Inflection of the exterior tentacles directly caused by objects left in contact with their glands--Periods of commencing inflection and of subsequent re-expansion--Extreme minuteness of the particles causing inflection--Action under water--Inflection of the exterior tentacles when their glands are excited by repeated touches--Falling drops of water do not cause inflection...19-37 [page vi.] CHAPTER III. AGGREGATION OF THE PROTOPLASM WITHIN THE CELLS OF THE TENTACLES. Nature of the contents of the cells before aggregation--Various causes which excite aggregation--The process commences within the glands and travels down the tentacles-- Description of the aggregated masses and of their spontaneous movements--Currents of protoplasm along the walls of the cells--Action of carbonate of ammonia--The granules in the protoplasm which flows along the walls coalesce with the central masses--Minuteness of the quantity of carbonate of ammonia causing aggregation--Action of other salts of ammonia--Of other substances, organic fluids, &c.--Of water--Of heat--Redissolution of the aggregated masses--Proximate causes of the aggregation of the protoplasm--Summary and concluding remarks--Supplementary observations on aggregation in the roots of plants...Pages 38-65 CHAPTER IV. THE EFFECTS OF HEAT ON THE LEAVES. Nature of the experiments--Effects of boiling water--Warm water causes rapid inflection-- Water at a higher temperature does not cause immediate inflection, but does not kill the leaves, as shown by their subsequent re-expansion and by the aggregation of the protoplasm-- A still higher temperature kills the leaves and coagulates the albuminous contents of the glands...66-75 CHAPTER V. THE EFFECTS OF NON-NITROGENOUS AND NITROGENOUS ORGANIC FLUIDS ON THE LEAVES. Non-nitrogenous fluids--Solutions of gum arabic--Sugar--Starch--Diluted alcohol--Olive oil-- Infusion and decoction of tea--Nitrogenous fluids--Milk--Urine--Liquid albumen--Infusion of raw meat--Impure mucus--Saliva--Solution of isinglass--Difference in the action of these two sets of fluids--Decoction of green peas--Decoction and infusion of cabbage--Decoction of grass leaves...76-84 [page vii.] 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...Pages 85-135 CHAPTER VII. THE EFFECTS OF SALTS OF AMMONIA. Manner of performing the experiments--Action of distilled water in comparison with the solutions--Carbonate of ammonia, absorbed by the roots--The vapour absorbed by the glands- -Drops on the disc--Minute drops applied to separate glands--Leaves immersed in weak solutions--Minuteness of the doses which induce aggregation of the protoplasm--Nitrate of ammonia, analogous experiments with--Phosphate of ammonia, analogous experiments with- -Other salts of ammonia--Summary and concluding remarks on the action of salts of ammonia...136-173 CHAPTER VIII. THE EFFECTS OF VARIOUS OTHER SALTS, AND ACIDS, ON THE LEAVES. Salts of sodium, potassium, and other alkaline, earthy, and metallic salts--Summary on the action of these salts--Various acids--Summary on their action...174-198 [page viii.] CHAPTER IX. THE EFFECTS OF CERTAIN ALKALOID POISONS, OTHER SUBSTANCES AND VAPOURS. Strychnine, salts of--Quinine, sulphate of, does not soon arrest the movement of the protoplasm--Other salts of quinine--Digitaline--Nicotine--Atropine--Veratrine--Colchicine-- Theine--Curare--Morphia--Hyoscyamus--Poison of the cobra, apparently accelerates the movements of the protoplasm--Camphor, a powerful stimulant, its vapour narcotic--Certain essential oils excite movement--Glycerine--Water and certain solutions retard or prevent the subsequent action of phosphate of ammonia--Alcohol innocuous, its vapour narcotic and poisonous--Chloroform, sulphuric and nitric ether, their stimulant, poisonous, and narcotic power--Carbonic acid narcotic, not quickly poisonous--Concluding remarks...Pages 199-228 CHAPTER X. ON THE SENSITIVENESS OF THE LEAVES, AND ON THE LINES OF TRANSMISSION OF THE MOTOR IMPULSE. Glands and summits of the tentacles alone sensitive--Transmission of the motor impulse down the pedicels of the tentacles, and across the blade of the leaf--Aggregation of the protoplasm, a reflex action--First discharge of the motor impulse sudden--Direction of the movements of the tentacles--Motor impulse transmitted through the cellular tissue-- Mechanism of the movements--Nature of the motor impulse--Re-expansion of the tentacles...229-261 CHAPTER XI. RECAPITULATION OF THE CHIEF OBSERVATIONS ON DROSERA ROTUNDIFOLIA. 262-277 [page ix.] CHAPTER XII.