THE PHYSIOLOGY OF PITCHER-PLANTS. 



101 



the descriptions and figures of the plants. In Vol. 53, 1826, 

 No. 2,629, N. phijllamphora is described, with the following re- 

 marks : — " According to some authors the water rises from the 

 roots, and is secreted into the vessels before the lid of the pitcher 

 has ever been opened ; and Rumphius observes that, in this state, 

 these curiously constructed vessels contain the most water, the 

 quantity of which diminishes after the lid opens, though even 

 then it fills again in the course of the night and evaporates in 

 the day ; but after the lid is quite shrivelled the water entirely 

 disappears. Loureiro, however, has a different opinion, and 

 attributes the presence of the liquid to the reception and preser- 

 vation of the night dews by the spontaneous opening and shut- 

 ting of the lid. What is the real fact does not seem to have 

 been as yet positively ascertained. In our plant, cultivated in 

 the stove, the young pitchers, before the lid opened, were, 

 Messrs. Loddiges observe, about one-third filled with a 

 sourish tasted water ; but after the lids opened, the water en- 

 tirely evaporated." Again, in Vol. 55, 1828, No. 2,798, in the 

 description of TV. distillatoria, the matter is referred to :— "Before 

 opening the lid, rather more than a drachm of limpid fluid was 

 formed within each of the largest pitchers of our specimen. This 

 had a sub-acid taste, which increased after the rising of the lid, 

 when the fluid slowly evaporated. My friend, Dr. Turner, per- 

 ceived it to emit, while boiling, an odour like baked apples, from 

 containing a trace of vegetable matter, and he found it to yield 

 minute crystals of superoxalate of potash on being evaporated to 

 dryness." 



Some years later an analysis of the liquid was made by 

 Voelker (Ann. Mag. of Nat. Hist., ser. ii., vol. 4, 1849), who 

 found that it gave a dry residue of about 0*9 per cent., consisting 

 of chloride of potassium, carbonate of soda, and lime and 

 magnesia in combination with malic and citric acids, together 

 with a trace of organic matter ; but this analysis does not appear 

 to throw any light upon the physiological importance of the 

 liquid. Nor do any investigations in this direction seem to have 

 been made until the whole question of "carnivorous" plants 

 had been raised by Darwin, when Sir Joseph Hooker made some 

 experiments on the digestive power of the liquid in these pitchers. 

 He found distinct evidence of digestive action on cubes of boiled 

 egg, raw meat, blood-fibrin, and cartilage (Address, Brit. Asso- 



