272 ABSOKPTION OF NUXKIMKNT BY INSKCTIVOKOUS PLA.NTS. 



cult to assure one's-self that they were two distinct plants ; on some 

 leaves of one were placed prepared flies, but none on the other. When 

 examined the one plant contained lithium, but the other did not contain 

 a trace ; if the lithium had been absorbed by the roots and not by the 

 leaves, could this have occurred? It was to remove this possible 

 doubt that the experiments of Series II. were instituted * 



Srries IL — Broker a rotuniifolia and D. intermedia. 



Locality. — The same as before. 



Method of preparation. — The plants experimented upon in this 

 Series were mostly those which were obtained growing in Sphac/num, 

 so that it was easily removed and the roots of the Droseras were left 

 uninjured. 



Six half-ounce wide-mouthed bottles were procured, and a 

 corresponding number of wooden stands constructed with holes in 

 the centres, and of such a height as to allow the necks of the bottles' 

 underneath them to stand about 1.5 cms. above the surrounding 

 surface. Over the necks were placed blotting-paper cones made from 

 discs six cms. in diameter, secured in this positition by pins ; the 

 roots of the plant then dipped into the water in the bottles through 

 holes at the summits of the cones. The water lost by absorption and 

 evaporation was replaced when necessary with a dropping- tube ending 

 in a long and fine point. 



Method of examination. — When the plants were examined the pre- 

 pared leaves were cut off, and then the cones and the plants were 

 placed in saucers, whilst the water from the bottles was poured into 

 evaporating dishes and reduced to a few drops. The cones were 

 examined with the spectroscope, as also were the various parts 

 of the Droseras, after being washed in distilled water and dried in 

 linen. 



The cones were employed, firstly, to prevent the lithium running 

 from the leaves (which were horizontal) up on to the stalks ; and 

 secondly, its getting to the roots : had this taken place the examina- 

 tion of the evaporated water, of the cones, and of the roots themselves 

 could not have failed to reveal its presence. 



Results of Series II. — The results thus obtained confirm those of 

 Series I. ; they are given in the following Table : — 



* The effect of the Hthium on the Droseras may be described as causing (when 

 the flies were soaked in a strong solution, excessive withering and shrinking of 

 the leaves and stalks to which it was applied, and occasionally the whole plant 

 was similarly affected. This could scarcely have occurred if absorption 

 had not taken place ; it produced the same effect when absorbed through the 

 roots. 



