the Nitrogenous Matter of Plants. 115 



To detect this portion of the circulation, considerable patience and 

 care are required. The canals in which it goes forward are, by 

 artificial light, more transparent than the membrane they per- 

 meate ; and in tracing their course little dilatations may be 

 observed to slowly form and presently vanish ; in these we have 

 the counterparts, on a minuter scale, of those dilatations seen to 

 arise during the contractions of the free canals stretched across 

 the cell-cavity. 



Lastly, to sum up this list of facts, if a still fresh hair be 

 selected, having however the primordial membrane of its cell de- 

 tached to a very limited extent from its cellulose wall, the same 

 movements are discernible in the unbroken filaments connecting 

 those two laminse of the cell ; only, owing to the extreme tenuity 

 of these filaments, the saccular dilatations are very minute, though 

 always visible by a magnifying power of 300 or 400 diameters. The 

 whole of the movements going forward within the intracellular 

 nitrogenous material are arrested when the cells are immersed for 

 a few minutes in an aqueous solution of sulphate of strychnine, 

 containing one part of the salt in 200 parts of water. The acetate of 

 morphine, of the same degree of dilution, produces similar effects, 

 though not in less than double the time taken by the strychnine. 

 The transparent hairs of Erodium moschatum, from the young 

 merithalli, are well suited for making these observations on. The 

 same may be said of the hairs of Chelidonium majus, Glaucium 

 glaucum, of the cellular tissue of the epidermis of Sedum, and of 

 that of the petiole of Dipsacus fullonwn and of Arum, &c, 

 except that in the last-named examples it is less easy to study 

 the phenomenon, because their vital movements are more obscure, 

 and their cellular walls less transparent. 



The movements that take place in the nitrogenous matter of 

 cells are not limited in their effects to the circulation of the gra- 

 nules contained in the canals and nucleus, but produce also an 

 incessant fluctuation in the aqueous fluid which surrounds them 

 and fills the cells, and so cause a movement of rotation of the same 

 character (though less marked, it is true) as that observed in the 

 cells of Chara, Nitella, Hydrocharis morsus-rance, of Stratiotes 

 aloides, &c. Still it is very visible, the liquid having numerous 

 small molecules suspended in it, if attentively observed ; and its 

 course may be detected in the hairs of Labiatse, &c. Thus there 

 are two sets of distinct movements within the interior of cells, — 

 one spontaneous, due to the contractility of the living material 

 itself; the other passive, dependent on displacement of the sur- 

 rounding liquid. 



In the exposition just made of the mode of existence of the 

 living matter of cells,' of its proper movements, and of those it 

 impresses on the fluid surrounding it ; our investigations have 



9* 



