ORGANS OF EEPRODrCTIOX. 



361 



form of an elongated tube through an aperture in the outer coat, 

 which ultimately bursts, and the tubular prolongation, by cell- 

 division, forms a thin, flat, green parenchymatous expansion, 



Fig. 787. 



Fig. 786. Capsules of a Fern {Marginaria 

 verrMCosa). s. Capsule, supported on a 

 stalk, p, and surrouuded hy a ring or 

 aniiulus, which is a continuation of the 

 stalk. One capsule Is represented as 

 burst on one side, and the contained 



spores in the act of being scattered. 



Fig.787. Germinating spore of a species of Fern. s. Spore, p. Pro- 

 thallium, r. Radical fibre. 



called a protkallium, p, from which one or more radical fibres, r, 

 are commonly produced in its earliest stage. On the under sur- 

 face of this body, there are soon produced two different struc- 

 tures, called antheridia and archegonia, which represent the 

 andrcecium and gynoecium of flowering plants. The antheridia 

 are stalked cellular bodies {fig. 788), containing other minute 



Fig. 788 



Fig. 788. Side view of an antlieridinm containing a number of .epermc^??*, 

 se. sp. Antherozoids escaping from the antheridium after having 



burst the sperm-cells. After Henfrey. Fig 789. Vertical section of 



an archegonium, passing through the canal and embryo-sac. After 

 Henfrey. 



