24 HISTORY OF BRITISH MOSSES. 



beyond the reach of the youtlifnl student, and is a most 

 interesting branch of study, we will, in as few sentences as 

 possible, state some of the most interesting facts recorded 

 and observations made, by those Botanists who have most 

 carefully studied this branch of Muscology. All who have 

 studied the internal structure of more perfect plants, know 

 that the compound organs, as they are called, — leaves 

 stems, roots, etc., — are made up of what are named "Ele- 

 mentary Tissues," divided into two great sections, the cel- 

 lular and vascular, as they consist either of minute cells 

 or vessels. As may well be imagined, they vary much in 

 form, size, and quantity. The latter are found only in the 

 more perfect plants; and as these descend in the scale, 

 we find — as in the case of Terns — the vascular tissue de- 

 creasing, till, when we reach the Mosses, all the organs are 

 formed of minute cells. Such is the case, for though 

 Hedwig, the celebrated German Muscologist, reasoning from 

 analogy and various phenomena, supposed they existed in 

 various organs, the most recent microscopic researches only 

 confirm the facts regarding the entire absence of tubular 

 vessels. The want of these however is amply compensated 

 by the varied form, delicacy, and absorbent properties of the 

 cells, which even to the naked eye are objects well cal- 



