ANNALS OF NATURAL HLSTORY. 



IX. — On the Structure of the Cellular Membrane in Mosses 

 and Hepaticae. By Dr. M. J. Schleiden*. 



It is doubtless an interesting subject of inquiry how far the cell 

 agrees in all plants in its vital phaenomena, and how far we are 

 thence justified in coming to the conclusion that the vegetable 

 cell is in all cases one and the same physiological element. For 

 this purpose detached remarks are not without value, and 

 their proper place will be assigned to the following statements. 

 If anything already known should be found amongst them, it 

 may be passed over. In the deluge of botanical literature it is 

 no longer possible, even with the best helps, immediately and 

 accurately to become acquainted in detail with everything 

 new ; and, indeed, when I noted down this observation I had 

 no library at hand. 



One of the most important and characteristic events in the 

 vital phaenomena connected with cellular tissue, is the thick- 

 ening of the membrane by a deposition of layers, the original 

 spiral arrangement of which will soon, it is to be hoped, be 

 universally established beyond doubt. Great importance has 

 already been attributed to spiral formations, but the conse- 

 quence resulting from them was too partially comprehended, 

 inasmuch as the porous kinds of tissue were excluded, though 

 these in reality are formed according to the same law. Now 

 if after so many new inquiries the idea must be proposed, 

 nay more, admitted, that we possess in the spiral formation an 

 elementary organ distinct from and opposite to the cellular 

 system, — that the spiral formation, including porous tissue, is 

 altogether but a characteristic portion of the vital process of 

 the cell, — so will this afford the means of determining whether 

 or not under the notion of cells are comprehended elements of 

 different importance. Where we find similar stages of de- 



• Wiegmann's Archiv fiir Naturgesch. V. Jahrg. Part IV. p. 277. 

 Ann. Nat. Hist. Yol. 5. ^o. 29. April 1840. a 



