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08 The Field Naturalises Quart ei^ly Nov. 



underground the plant continues to grow in the spaces be- 

 tween the roots of its hosts until it may attain the weight of 

 many pounds. The underground stem is formed like the 

 stem which bears the inflorescence, and has thick fleshy 

 leaves. At the lower end of the leaves, just where they are 

 attached to the stem, there is a semicircular canal formed by 

 the involution of the dorsal end of the leaf. About ten 

 chambers, being excavations in the dorsal substance of the 

 leaf, are entered by minute passages from this canal. These 

 chambers are lined with cells of two kinds — one set being 

 capitate, the other dome-shaped. When the cells are stimu- 

 lated they send out protoplasmic filaments similar to those 

 which we see under the microscope in rhizopods and other 

 protozoa, such as the Wheel and Sun animalcules. Now, 

 small animals in search of food or shelter enter these cham- 

 bers by the passages. They enter, but do not return, for the 

 stimulus of their presence causes the cells to extrude the 

 filaments which bar their exit. The filaments envelop the 

 animals just as the amoeba seizes its prey, and soon there is 

 nothing left but chitine and other indigestible matter ; every 

 particle of nourishment which their bodies contained has 

 been absorbed by the protoplasm of the filaments. 



Now, here there is no secretion, no provision of a peptic 

 ferment, such as we find in other insectivorous plants, no 

 interference from the outside as by the bacteria of putrefac- 

 tion, but the protoplasm of the cell in its individual life acts 

 itself as a ferment for the preparation of the food and fits 

 it for transmission from cell to cell for the nourishment 

 of the plant. 



We have seen that toothwort is a parasite, and derives a 

 large portion of its nourishment by abstracting the elaborated 

 sap from the roots of trees growing near it ; indeed sometimes 

 these tree-roots may be seen covered as if by lacework with 

 the adherent fibrous rootlets of the toothwort. The process 

 which issues from the disk by which the rootlets adhere, and 

 which is named the sucker or haustorium, penetrates the 

 roots as far as those vessels between the cambium and the 

 bast, which are known as sieve tubes. These tubes are filled 

 with an " amorphous proteinaceous slime," as Sachs says, 

 which is not protoplasm, but circulating proteids in a state 



