MOSSES. 



319 



Conomiln'um julianiim and CincUdotus aquaticus, which hkewise have the power of 

 detaching themselves. 



The Sexual Orgajis of Mosses usually occur in considerable numbers at the 

 end of a leafy axisS surrounded by enveloping leaves often of peculiar shape, 

 and mixed with paraphyses. A compound structure of this kind may, for the 

 sake of brevity, be called a * Flower.' The flower of Mosses either terminates the 

 growth of a primary axis (Acrocarpous Mosses), or the axis is indeterminate, and 

 the flower is placed at the end of an axis of the second or third order (Pleurocarpous 



FiC. ly^.— Tetrnphis fiellucirla; A a plant producing fremni.Te 

 (natural size) ; A' the same, magnified ; y the cup in which the 

 genimsc are collected ; C longitudinal section through the sum- 

 mit of the plant, b the leaves of the cup. K the gemmae in 

 various stages of development ; the older ones are forced off 

 their stalks by the later growth of the younger ones, and forced 

 over the side of the cup; D a mature gemma (xsoo), consisting 

 at the margin of one, in the centre of several layers of cells. 



Fig. -z-^T.—Tetraphis feUucida ; A, 6 a. gemma, detached from 

 its stalk at a, the protonema-filament xy has been formed by tlie 

 growth of a marginal cell of the gemma, and the flat structure/ 

 as a lateral outgrowth from the protonema ; this has also put 

 out root-hairs w.iv'.tu" (xioo); B,/> a flat pro-embryo from 

 the base of which a leaf-bud A' and root-hairs w, w' have sprung ; 

 the base of the pro-embryo often puts out a number of new flat 

 pro-embryos before a leaf-bud is formed. 



Mosses). Within a flower either both antheridia and archegonia are produced 

 (bisexual flowers), or it contains only one kind of sexual organ, and the flowers 

 may then be either monoecious or dioecious. Sometimes the male flowers appear 

 on smaller plants with a shorter duration of life (as Fiinaria hygrometrica, Dicranum 

 undulatum, &c.). In external appearance the bisexual are similar to the female 



The male branches of Sphagnum form an exception {vide infra). 



