354 



BOTANY. 



below, where there are two layers. The neck of the arche- 

 gonium at first contains an axial row of cells, but these 

 become dissolved and transformed into a mucilaginous mass 



just before the time of 

 fertilization. The germ- 

 cell lies in the lower 

 swollen portion of the ar- 

 chegonium ; it consists of 

 a naked rounded mass of 

 protoplasm. At the time 

 of fertilization the upper- 

 most cells of the neck of 

 the archegonium diverge 

 from one another, and 

 thus form an open chan- 

 nel to the germ-cell. 



463. Fertilization 

 takes place in the water, 

 or in the presence of a 

 considerable amount of 

 moisture. The spermato- 

 zoids, which are produced 

 in great numbers, move 

 through the water by 

 means of their vibratile 

 cilia, and some of them 

 find their way down the 

 channels of the archego- 



Fte!m-Development of the sporogonium nia > wll6re they Unite their 



|^5t4'&!8SKig ^bstance with the germ- 



tihzatiou ; h, neck ; /, apical portion of young cells. As a 1'CSult of this 

 sporogonium ; f, basal portion of young sporo- 

 gonium. B, vertical section of a female flower; Union, the germ-Cell SUT- 

 f, young sporogonium elongating, and carrying n ., ij. . X1 ?1 

 up the remains of the old archegonium, o (now 1'OUnuS ItSell Wltll a Wall 

 called the calyptra) ; A, neck of old archego- / n i -t 

 nium. C, a later stage of the same. In and OI Cellulose, and SOOn Un- 

 C the sporogonia are seen to be growing down- ;jp ro . np(} /HviVrm in virirm <? 

 ward into the tissues of the leafy stem. A X c GrgOCS llVlSiO 



500 ; B and c much lessAfter Sachs. directions, giving rise to a 



many-celled mass, the young sporogonium (/, f, Fig. 243, 

 A). In most Mosses the young sporogonium elongates rap- 

 idly, and while its upper end carries up the remains of 



