THE PAGE OF NATURE. 25 



being slender hair-like plants ; some resembling minia- 

 ture fir-trees, others cedars, and others crested feathers 

 and ostrich plumes. In size they vary from a minute 

 film of green scarcely visible to the naked eye, to several 

 feet in length. Nor are their colours less variable, rang- 

 ing from white, through every shade of yellow, red, 

 green, and brown, to the deepest and most sombre black. 

 Though most of the peculiarities of mosses are visible 

 to the naked eye, it is on the stage of the microscope 

 that they appear to the greatest advantage. The modi- 

 fications of structure to suit the requirements of their 

 economy thus revealed, cannot fail to excite our admira- 

 tion and astonishment. The stems of mosses, though 

 serving the same purposes, are widely different from 

 those of flowering plants. We are ignorant of the 

 manner in which they are developed. Probably, like 

 endogenous plants, which is the least complicated of the 

 two natural processes of increase in the vegetable king- 

 dom, they grow by successive additions to the summit, 

 always proceeding from the interior, never increasing the 

 diameter after their outer layer has been formed. They 

 are solid, and composed entirely of cellular tissue, which 

 gradually becomes softer and more porous near the centre, 

 uniform in every part, having neither medullary rays, 

 nor true outward bark, nor central pith, nor even the 

 scalariform vessels observable in the stems of ferns. Of 

 the course taken by the ascending and descending sap, 

 we are equally ignorant, if indeed there really exist in 

 them currents similar to those of flowering plants, which 

 may be more than doubted. The roots are exceedingly 

 delicate organs, and yet they take as firm a hold of the 



