40 THE FLOEAL WORLD AND GARDEN GUIDE. 



taking notice of the conditions under which they are found, a good 

 idea of the treatment they require may be formed by those who 

 know little or nothing about the subject. The cultivator will find 

 every bit of information picked up in this way of very great service 

 to him, at some time or other. 



The undermentioned species are all particularly beautiful, and 

 have the great merit of thriving uncommonly well upon an artifi- 

 cially-constructed rockery: Bartramia fontana, B. jpomiformis, Bryum 

 alpinum, B. capillar e, B. argeiiteum, Dicranum squarrsoum, Grimmia 

 Doniana, G. leucophcea, G. pulvinata, Hookeria lucens, Hypnum 

 denticulatum, H. cttpressiforme, H. purum, H. Bchreberi, H. splendens-,. 

 Leslcea sericea, Macomitrium canescens, Weissia contraversa, the 

 principal species of Tortula, and all the Polytrichums, and Mniums. 



The fructification of mosses is a very interesting subject, and the 

 microscopist cannot well find more beautiful objects than their 

 varieties afford. A close examination of the organs of repro- 

 duction proves that the same principles prevail as in plants of 

 higher structure, and, like them, the mosses have both male and 

 female flowers, and from these last the seeds are developed. During 

 winter and early spring, most of the mosses put forth slender hair- 

 uke threads, which are surmounted with capsules, in which are 

 contained the seeds. There is this striking difference between the 

 fructification of mosses and true flowering plants ; that, whereas in 

 the latter it is the german, or lowest part, that swells into a seed- 

 vessel, in the moss it is the summit that becomes the receptacle for 

 the seeds or spores. "When the seeds are ripe, the extinguisher-like 

 cap is either lifted off entire, or split down its whole length, and 

 the seeds are then scattered to the winds. When the seeds germi- 

 nate, they produce a number of delicate confervoid threads, out of 

 which, after a time, the true moss-like growth proceeds, and in its 

 season acquires fruitfulness. Many of the patches of greenness 

 on stone walls and gravel walks, which exhibit no distinctness of 

 form to the eye, and appear rather like a green slime than true 

 vegetation, are mosses in their first stage of development. If the 

 nidus upon which they first appear proves suitable, their true 

 character as mosses soon appears ; but if the nidus is unsuitable, 

 they continue for some time in a confervoid form, and then dis- 

 appear. 



There are some very distinctive features in the structure and 

 fructification of mosses. The Bryums have strong roots ; the 

 Hypnums have very small and delicate roots. Some mosses which 

 grow on rocks and trees have merely a flattened disk for their 

 attachment, the plants deriving nourishment from the atmosphere 

 exclusively, while Bartramia arcuata produces such a profusion of 

 roots, or what are supposed to be roots, that the leaves and stems 

 are completely smothered with them. Many species emit roots at 

 their points, as they creep along, and Hookeria lucens emits roots 

 from every point of substance, even from the edges and surfaces of 

 the leaves. Generally, mosses have true stems and leaves ; but in 

 some instances the fruit-stalk rises directly from the root. How- 

 ever, even in these cases, true leaves are produced, though there are 



