ADDRESS. 1 3 



ever as not to bruise its tissues, or in any way wound it, the blow will 

 sometimes be immediately followed by a drooping of the stem com- 

 mencing at some distance above the point to which the stroke had been 

 applied : its strength appears to have here suddenly left it, it is no longer 

 -able to bear its own weight, and seems to be dying. The protoplasm, 

 however, of its cells, is in this instance not killed, it is only stunned 

 by the violence of the blow, and needs time for its restoration. After 

 remaining, it may be for some hours, in this drooping and flaccid state, 

 the stem begins to raise itself, and soon regains its original vigour. 

 This experiment will generally succeed well in plants with a rather large 

 terminal spike or raceme when the stroke is applied some little distance 

 below the inflorescence shortly before the expansion of the flower. 



In the several instances now adduced the protoplasm is in the mature 

 state of the plant entirely included within a wall of cellulose. Some re- 

 cent beautiful observations, however, of Mr. Francis Darwin, have shown 

 that even in the higher plants truly naked protoplasm may occur. From 

 the cells of certain glandular hairs contained within the cup-like recep- 

 tacles formed by the united bases of two opposite leaves in the Teazel 

 (Dipsacus) he has seen emitted long pseudopodia-like projections of the 

 protoplasm. What may be the significance of this very exceptional 

 phenomenon is still undetermined. It is probably, as Mr. Darwin sup- 

 poses, connected with the absorption of nitrogenous matter. 



That there is no essential difference between the protoplasm of plants 

 and that of animals is rendered further evident by other motor phe- 

 nomena, which we are in the habit of regarding as the exclusive attribute 

 of animals. Many of the more simply organised plants give origin to 

 peculiar cells called 'spores,' which separate from the parent, and, like the 

 seeds of the higher plants, are destined to repeat its form. In many cases 

 these spores are eminently locomotive. They are then termed ' swarm- 

 spores,' and their movements are brought about, sometimes by changes 

 of shape, when they move about in the manner of an Amoeba, but more 

 frequently by minute vibratile cilia, or by more strongly developed 

 flagella or whip-like projections of their protoplasm. These cilia and 

 flagella are absolutely indistinguishable from similar structures widely 

 distributed among animals, and by their vibratory or lashing strokes 

 upon the surrounding water the swarm-spores are rapidly carried from 

 place to place. In these motions they often present a curious sem- 

 blance of volition, for if the swarm-spore meet with an obstacle in its 

 course, it will, as if to avoid it, change the direction of its motion, and 

 retreat by a reversion of the stroke of its cilia. They are usually 

 attracted by light, and congregate at the light side of the vessel which 

 contains them, though in some cases light has the opposite effect on them 

 and they recede from it. 



Another fact may here be adduced to show the uniform character of 

 protoplasm and how very different are its properties from those of lifeless 

 matter, namely, the faculty which all living protoplasm possesses of 



