MOSSES 59 



acrocarpous, and fig. 19 a pleurocarpotis plant. 

 In the former class must be included those plants, 

 of which there are not many, where the fruit is 

 found growing from the end of short shoots, which 

 hranch off from the main stem. From a hard-and- 

 fast scientific point of view this classification is not 

 accepted to the same extent as it formerly was ; 

 but the cases where it is not strictly applicable 

 are so comparatively few, and are so unlikely to 

 trouble a beginner that we may, for present 

 purposes, disregard them. The distinction between 

 these two general types of moss-growth is so clear, 

 that the student will soon learn to recognise them, 

 even in the field, without any difficulty, and this 

 preliminary diagnosis will at once tell him among 

 which genera he must search for the particular 

 plant in question. Those mosses in which the 

 fruit is produced at the end of the stem have a 

 distinctly upright growth, and many of them 

 frequently congregate in tufts or cushions, owing 

 to the very nature of their mode of development ; 

 for the formation of flowers, and afterwards of 

 fruit, at the end of the principal stem, stops its 

 further increase in that direction, and the tendency 

 consequently is to put forth new branches, and 

 so to add to the size of the tufts. On the other 

 hand, plants that have the fruit arising from 

 the side of the stem are not subject to the same 

 check to their elongation; and, as the stem thus 

 tends to increase considerably in length, such 



