glQ I'LANT STUDIKS 



gametoiiliyte ; the Jutiyermatuiiu line has differentiated 

 tlie form of tlie ganietojthyte ; the AntJioccnin line has 

 dilferentiated the structure of the sporophyte. It sliould 

 be remembered that other cliaraeters also serve to distin- 

 guish the lines from one another. 



Musci (J/tisA'e-s) 



20(1. General character. — Mosses are highly si)ecialized 

 plants, probably derived from Liverworts, the numerous 

 forms being adapted to all conditions, from submerged to 

 very dry, being most abundantly displayed in temperate 

 and arctic regions. Many of them may be dried out com- 

 pletely and then revived in the presence of moisture, as is 

 true of uuuiy Lichens and Liverworts, with which forms 

 Mosses are very commonly associated. 



They also have great p)owcr of vegetative multijilica- 

 tiou, new leafy shoots putting out from old ones and from 

 the protonema indefinitely, thus forming thick carpets and 

 masses. Bog mosses often completely fill up bogs or snudl 

 ponds and lakes with a dense gi'o\\'th. which dies lielow 

 a.nd continues to grow above as long as the conditi<jns are 

 favoralile. These quaking l)ogs or " inosses," as they are 

 sometimes called, furnish very treacherous footing unless 

 rendered firmer by other plants. In these moss-filled bogs 

 the water and silt shut olT the lower strata of moss fi-inu 

 complete disorganijiation, and they Ijecome modified iiilu a 

 coaly sul)stanco called jimt. which may accumulate to cou- 

 sideralile thickness l)y the contiiiued ujiward growlii of the 

 mass of moss. 



The gameto])hyte body is diUV^i'entiated into iwo very 

 distinct regions : (1) the ]irostrate dorsiventral tliallus, 

 which is calle(l protonenni in this group, and wbi(>h may 

 bo either a broad Hat tliallus oi a. set. of branching lila- 

 meiits (i''igs. ■.'7."), 2'.)(l) ; ("i) the erect leal'v braiu'li or 

 gametoph(.)re ( i''ig. ''TO). This erect branch is said to be 



