ABSORPTION. O 



the altitude of the flowering stem of the American Aloe, Agave 

 Americana, as I returned to my home in the evening from what it had 

 been in the morning as I passed on my way to Capetown. Dr Asa 

 Gray, wi'iting on the cell increase in this gigantic peduncle, says, — 

 " After waiting many years, or even for a century, to gather strength 

 and materials for the effort. Century Plants which grow in our con- 

 servatories send up a flowering stalk which grows, day after day, at 

 the rate of a foot in twenty-four hours, and becomes about six inches 

 in diameter. This, supposing the cells to average l-300th of an inch 

 in diameter, requires the formation of over twenty thoicsand millions 

 of cells in a day ! " 



It is by such cell production, development, and multiplication 

 that the growth of all plants, from the Snow Plant to the monarch of 

 the wood, is effected ; nor is it without consideration that I make use 

 of the term multiplication in speaking of the increase of their number, 

 for it is the case that it is by such metrical progression that the 

 increase is effected. Not only may each cell be studied as in itself a 

 complete oi'ganism, an integer, and consequently an integral part of 

 the more comprehensive structure into which it enters — as a man is 

 in himself complete, an integei', and, consequently, an integral part of 

 the nation to which he belongs, and as such may be made the subject 

 of study apart from the other men of whom, along with him, the 

 nation is composed, — but, in the Red Snow, we have a single cell 

 constituting a complete plant ; and in this we may study more 

 conveniently some of the phenomena of vegetation on which some of 

 the alleged meteorological effects of forests depend as consequences. 



The absorption of moisture appears to be an invariable concomitant 

 of cell growth and, consequently, of cell development and cell 

 increase. We may afterwards enquire what function the moisture 

 fulfils in the vegetable economy, at present it is only the fact and the 

 mode of its accomplishment which are brought under consideration. 



A cell is too minute for ocular demonstration of the mode of 

 absorption of moisture through the cell wall to be given by it. 

 The cells vary in different plants, from about the thirtieth to the 

 thousandth of an inch in diameter ; an ordinary size is from 1-3 00th 

 to l-500th of an inch, so that there are generally from 27 to 125 

 millions of cells in the compass of a cubic inch of vegetable cellular 

 structure. In cells so minute occular demonstration of the modus 

 operandi is not to be expected. But they have been spoken of as 



