132 



SCIENCE-GOSSIP. 



CIRCULATORY MOVEMENTS OF PROTOPLASM. 



By H. E. Griset. 



'THE following notes are from my own ob- 

 serrations, both physiological and anatomical. 

 I am led to believe they may prove acceptable to 

 other students of botany. 



Hydrocharis morsus-rana, Linn. — The circulation 

 of the protoplasm is very plainly seen in the cells 

 of the tissue which forms the spathaceous bracts 

 of these plants, several of which should be kept at 

 hand in a basin of water for study. With the 

 forceps and the aid of the scalpel remove — with the 

 least injury possible — one of the membranous 

 bracts from the base of a leaf, and place it in the 

 live-cage, or on a clean slip, with the addition of a 

 drop of water ; it may then be focussed under a 

 power of 200 or 300 diameters. Generally at first 

 the rotation is not observed, owing to the disturb- 

 ance occasioned by the detachment ; but after a 

 minute or two slight irregular movements will be 

 seen in some younger cells. These ultimately blend 

 themselves as it were into a slow circulation, which 

 will continue to increase in quickness for a short 

 time, until a circulation peculiar to the age of the 

 cell has been attained. To complete the circuit of 

 the cell-wall it will require from thirty seconds in 

 tbe nascent ones to two minutes in the elder ones. 

 With these circulating currents of protoplasm most 

 of the lenticular chlorophyll corpuscules (and often 

 the nucleus also, around which they agglomerate) 

 are carried on. 



Alisma plantago, Linn. — In the irregular stellate 

 merenchymatous tissue of the septa of the air- 

 canals, from the petiole or peduncle, this intra-cellular 

 circulation is again beautifully illustrated. In all of 

 these cells most of the chlorophyll corpuscules ag- 

 glomerate around the nucleus, and this mass, with a 

 few free corpuscules, circulates upon the slender 

 reticulated parietal cords of protoplasm. The 

 nucleus amassed with the chlorophyll corpuscules 

 does not continue its circulation without interrup- 

 tion as would be supposed, but sometimes stops or 

 travels more or less quickly. This circulatory 

 movement of the protoplasm has been seen in 

 many others, especially aquatic plants, and is well 

 seen in a natural state in the hairs of some of the 

 Phanerogamia, like the potato. It probably con- 

 tinues throughout the whole life of the cells in 

 most aquatic plants, or perhaps in all the cells 

 where it has been observed, whether in plants of 

 an aquatic habit or otherwise, but it is certainly 

 less active in the older cells. In the cells of the 

 parenchymatous (irregular stellate merenchvma- 

 tous) tissue of the leaves in which it also takes 

 place, the circulation is more active in the cells of 



the interior than the exterior of the tissue, but here, 

 on account of the opacity and complexity of the 

 tissues, it is far more difficult to see than in the 

 spathaceous bracts of Hydrocharis, which consist 

 simply of two layers of cells. Thin sections cut 

 from leaves should be restored to activity by 

 placing them in tepid water or otherwise. 



In very young cells the protoplasm is vacuolated, 

 that is, the " cords " are not parietal (but usually 

 become so as the cell increases in age) ; at this 

 period the chlorophyll corpuscules traverse these 

 " cords " to and from the nucleus which remains 

 motionless in the centre of the cell, forming the 

 point of radiation of the cords. That it is the 

 protoplasm that circulates is confirmed by the 

 minute constituent granules. Phenomena of this 

 kind are always best observed in the youngest cells 

 (like those nearest the epidermis in newly-formed 

 septa of A . plantago), when viewed by the aid of the 

 parabola. Henfrey describes these " movements 

 of the protoplasm " as follows : " During the time 

 when the protoplasmic contents of young cells are 

 becoming hollowed out into spaces filled with 

 watery cell-sap, a regular movement of this 

 protoplasm takes place, which may be observed 

 very readily in young hairs of Phanerogamic plants, 

 and which probably takes place in an early stage 



Fig. 1. — Cells from a septum of Alisma plantago, s. 380. 



in all other structures. This movement, which is 

 erroneously called rotation of the cell-sap, is a circula- 

 tory movement of the protoplasm made perceptible 

 by the minute opaque granules which exist in the 



