214 



REPRODUCTION 



a very early period of its develogment, d, we find the sporangium 

 composed of a protoderm and a central cell. The protoderm 

 proceeds to the formation of an epidermis or sporangium wall, 



Mature tapetum of 

 ell layers 



Tapetal Plasmodium 



formed by fusion of 



tapetal protoplasts ^^ _^^^ ,,«,,, 



tewtnt . *««fe y\f<^ n ::*-*-£' « -i^^m i / Mother cells have divided 



to form four spores only 

 three shown 



Grandmother-cell has divided 

 producing two mother-cells 



Fig. 1 2 2. ^Sporangium and spore formation of a fern, Aneimia Phyllitidis. ii, growing 

 apex; i, group of three protodermal cells which are to give rise to a sporangium; b, c, d, e, 

 f, g, h, successive stages in sporangium and spore formation. Partly diagrammatic. 

 Further description in the text. 



