370 THE CANADIAN NATURALIST. [Vol. vii. 



its infantine state — the analogy here with the mature plants 

 which feed on organic food seems to be complete. 



But we are beginning also to recognise the fact that there 

 are a large number of flowering plants that pass through their 

 lives without ever doing a stroke of the work that green plants 

 do. These have been called Saprophytes. Monotropa, the 

 curious bird's nest orchis (^Neottia nidus-avis), Epipogium, and 

 Corallorhiza are instances of British plants which nourish them- 

 selves by absorbing the partially decomposed materials of other 

 plants, in the shady or marshy places which they inhabit. They 

 reconstitute these products of organic decomposition, and build 

 them up once more into an organism. It is curious to notice, 

 however, that the tissues of Neottia still contain chlorophyll in a 

 nascent though useless state, and that if a plant of it be im- 

 mersed in boiling water, the characteristic green colour reveals 

 itself. 



Epipogium and Cordlorhiza have lost their proper absorbent 

 organs ; they are destitute of roots, and take in their food by the 

 surfaces of their underground stem structures. 



O 



The absolute difi"erence between plants which absorb and 

 nourish themselves by the products of the decomposition of plant- 

 structures, and those which make a similar use of animal struc- 

 tures, is not very great. We may imagine that plants accident- 

 ally permitted the accumulation of insects in some parts of their 

 structure, and the practice became developed because it was 

 found to be useful. It was long ago suggested that the receptacle 

 formed by the connate leaves of Dipsacus might be an incipient 

 organ of this kind ; and though no insectivorous habit has ever 

 been brought home to that plant, the theory is not improbable. 



Linugeus, and more lately Baillou, have shown how a pitcher 

 of Sarracenia may be regarded as a modification of a leaf of the 

 Nympliaea type. We may imagine such a leaf first becoming 

 hollow, and allowing debris of different kinds to accumulate ; 

 these would decompose, and a solution would be produced, some 

 of the constituents of which would diffuse themselves into the 

 subjacent plant tissues. This is in point of fact absorption, and 

 we may suppose that in the first instance — as perhaps still in 

 Sarracenia purpurea — the matter absorbed was merely the saline 

 nutritive products of decomposition, such as ammoniacai salts. 

 The act of digestion — that process by which soluble food is re- 

 duced without decomposition to a soluble form fitted for absorp- 

 tion — was doubtless subsequently acquired. 



