128 MOSSES AND LIVERWORTS 



the germ-cell (oosphere) in the hollow base, which 

 hy this time has increased considerably in size, 

 and completely fills up the large central cavity 

 inside which it was formed. It might seem, at 

 first sight, as though the cup would prove an 

 obstacle to fertilisation, but as a matter of fact 

 this is not so ; indeed, fertilisation is sometimes 

 effected when it is but half formed, and when 

 its walls are comparatively low. And even where 

 this is not the case the fertilising body has little 

 or no difficulty in finding its way to the interior. 



After fertilisation the spore-vessel or capsule 

 begins to develop inside the swollen base of the 

 fruit-bearing organ, and as it increases in size 

 this swollen base swells more and more, becoming, 

 in course of time, very much enlarged (see 

 Plate IX. fig. 5). This enlarged base of the 

 flower is now known as the Yeil or calyptra, a 

 term which, it will thus be seen, does not bear 

 precisely the same meaning as it does when used 

 in reference to a moss. There it signifies the 

 upper portion only of the fruit-bearing organ, 

 which was torn off when the young capsule burst 

 through its prison walls (see page 43), and this 

 is carried up on the end of the capsule ; while 

 here the term signifies the whole swollen base 

 of the fruit-bearing organ inside which the fruit 

 is formed, and which is never rent into two 

 portions when the capsule makes its way out. 



At Plate IX. fig. 9 will be found a drawing of 



