30 CONNECTICUT GEOL. AND NAT, HIST. SURVEY. [Bull. 



DISTRIBUTION OF THE BRYOPHYTES IN CON- 

 NECTICUT ACCORDING TO ENVIRONMENT 



Even to the casual observer it is evident that the character 

 of the vegetation which clothes the surface of the earth varies 

 greatly under different conditions. There is a marked con- 

 trast, for example, between the impenetrable tangle of a 

 tropical jungle w'ith its wide diversity of species, and the 

 northern spruce forests which are relatively open and are made 

 up of comparatively few species. The vegetation at the sum- 

 mit of Mount Washington is scant and limited to shrubby 

 and herbaceous plants, while the valleys but a few thousand 

 feet below are heavily wooded. Ordinary land plants differ 

 strikingly in appearance from seaweeds and other submerged 

 aquatics. 



These are perhaps extreme illustrations, but innumerable 

 examples of i this adaptation to environments which are less 

 diverse may be seen everywhere. The vegetation in an open 

 field presents a decided contrast to that of a pine grove but 

 a few hundred yards distant, while the flora in a bog is totally 

 different from that in a meadow. 



It may be stated as a general rule that every plant is best 

 adapted to a peculiar environment, and that for every species 

 there are certain more or less well defined limits outside of 

 which it cannot exist. What is true of the higher plants applies 

 even more forcibly to the Mosses and Hepatics, for, as Les- 

 quereux remarks, " these humble and apparently useless beings 

 have their geological and lithological preferences far better 

 marked than any other kind of vegetable."* 



The factors which produce this environment and determine 

 these limits are numerous, but the following are the most 

 important : 



•Quoted by Mohr: Plant Life of Alabama. Contr. U. S. Nat. Herb., 6: 292. 1901. 



