INTERNAL STRUCTURE. 25 



culated to draw forth our admiration and invite us to their 

 study. 



In the stems and leaf-veins they are, from the pressure 

 from witliin, of a lengthened form, resembling the tubes 

 found in the wood of trees ; while in the expanded portion 

 of the leaf they assume many shapes, being round, oblong, 

 and variously angled ; and tliese forms are so constant in 

 each species, that specific characters may in many instances 

 be deduced from them. 



From the densest portion of the stem being that which 

 is external, a similarity may be traced between Mosses and 

 Palms, while, from their extensive ramification, and other- 

 wise complicated forms, they seem to bear considerable 

 analogy to plants of a higher order. 



In Sphagnum and some other genera, the cells are tra- 

 versed bv bars in various directions, which render them 

 beautiful objects for the microscope, and they are doubtless 

 of importance in the economy of the plauf^. 



* Recent authors of worlds ou Mosses Lave luacle use uf characters taken 

 from the structure of the cclluUir tissue, forformiuG: subdivisious of genera. 



