10 Prof. Reichert on the Sap-currents, 



plopods, again, the legs are equal, and terminate in a simple 

 claw, which is not the case in Pauropus. The mouth-parts, 

 though very different from those of the Chilopods, are perhaps 

 even less like those of the Diplopods. The eyes and antennse 

 are also very different. 



Thus, then, Pauropus differs greatly from either of the two 

 great orders of Centipedes. It forms a connecting link not 

 only between the Myriapods and other Articulata, but also be- 

 tween the Chilopoda and Diplppoda. 



III. — On the Sap-currents {Rotation and Circulation in the Cells 

 of Plants), with reference to the question of Contractility. By 

 Professor Reichert*. 



The results of my investigations may be summed up in the 

 following paragraphs : — 



1. In all vegetable cells with rotating, circulating, or rotato- 

 circulating currents, two parts are to be distinguished in the 

 contents of the cellulose capsule — namely, the central "cell-juice^^ 

 or "cell-fluid'^ situated in the axis, and the "mantle-layer" 

 [Mantelschicht) diffused between this and the cellulose capsule. 



3. The " cell-fluid '' is colourless, or coloured as in Trades- 

 cantia virginica, not very tenaciously fluid, and without albumen, 

 but not well known as regards its other chemical properties; 

 with respect to the circulation, it is the motionless, resting part 

 of the cell-contents. 



3. To the " mantle-layer ^' belong the following constituents : 

 — the " mantle-fluid " as I have called it, the tenaciously fluid 

 substance named " protoplasm '^ by Hugo Mohl ; chlorophyl 

 corpuscles, and other very small solid corpuscles, the chemical 

 nature of which cannot be ascertained positively; the cell-nucleus; 

 microscopic crystals; and the primordial utricle when this is 

 present, which would form the boundary of the " mantle-layer " 

 towards the cellulose capsule. 



4. In the Characese the " mantle-fluid" cannot be overlooked ; 

 it was, however, erroneously assimilated to the tenacious fluid 

 substance of circulating sap-currents, the so-called protoplasm- 

 currents, and rightly distinguished only by Nageli. In the cells 

 with circulating sap-currents, it was first detected by E. Briicke 

 in the stinging- hairs of Urtica urens ; and it was observed in all 

 the cells with rotating or circulating sap-currents examined by 

 me. It is diffused between the cell-juice and the cellulose cap- 

 sule, or the primordial utricle when this is present, is fluid, rich 



* Translated by W. S. Dallas, from the Monatsbericht der Akad. der 

 Wiss. zu Berlin, 3rd May, 1866, pp 318-523. 



