GEOWTH WITHOUT LEAVES. 75 



its weight at the time when the stem perished, but as it con- 

 tinued to grow for nine years and a half, and was originally in 

 a small pot, it is not unreasonable to assume that it had 

 acquired at least seven times its original weight. Although no 

 leaves had been formed, yet many attempts at the production 

 of stems were visible upon the specimen, in the form of short 

 stunted tubercles or incipient branches ; and the root was in 

 1853 full of vitality. Here we have a striking proof that 

 plants may possess an inherent power of growth without leaves. 

 It is probable that in this case the bark, of which a large 

 surface had been exposed to light, acted as a substitute for 

 foliage, perspiring, and assimilating food, as all green parts do, 

 whether leaves or not. It is also possible that the surface of 

 the root which rested upon the earth, had constantly attracted 

 from the soil the food which the bark is assumed to have 

 assimilated. But if such a power can be recognised in an 

 Ipomoea, we must also admit its existence in the tuber of a 

 Potato, even although that tuber is not exposed to light ; and 

 the vital force of the latter must be allowed to be capable not 

 only of converting into starch the gum supplied by the leaves, 

 but of absorbing gaseous and fluid matters from the soil, and, 

 by their assimilation, of continuing to grow, although perhaps 

 for only a limited time. 



M. Dnrand, of Caen, arrived at similar oonclusions. In some experi- 

 ments published in the Comptes Hendus, Aug. 16, 1852, it was foxmd 

 that Poplars, Apple-trees, Acacias, &c., on which nothing was left 

 except Miselto, grew in diameter notwithstanding the loss of their 

 green organs. The two following experiments were more especially 

 conclusive : — Exp. 1. At a yard and a half above the soil, an old Elm- 

 tree was cut across before winter. The tree thus mutilated was a mere 

 fragment of trunk under whose baxk some adventitious buds were 

 collected, so as to form a bur. The wound was covered with plastic 

 clay. As soon as the adventitious buds began to move in the spring, 

 they were carefully removed as fast as they appeared. Nevertheless, a 

 layer of wood was formed. In the following years the same thing hap- 

 pened, that is to say, in the absence of leaf-buds, leaves, or any green 

 parts, a layer of wood was formed every year ; and it was ascertained 

 that the roots of the Elm under experiment were not accidentally 

 grafted with the roots of other Elms, as is said to have been the case 

 with the Fir-trees brought into notice by Dutrochet, Lime-trees 



