274 



ELEMENTARY STUDIES OF 



examine it closely we shall see that it is not a 

 flower. 



What are spores? These bodies, when sown under 



VEIN 



/ 

 ^SPORANGIA 



Fig. 154. Sporangia of Male Fern. 

 Transverse section through a pinnule and sorus. The spores are within the sporangia. 



.SPORE 



B 



ANTHERIDIA 



RHIZOIDS ' 



Fig. 155. Germination of Spore and Development of Prothallus of Fern (A and B). 



The archegonia and antheridia are the female and male elements respectively. 



C, Under side of Prothallus. 



suitable conditions of soil, moisture, heat and light, give 

 rise to very small heart- shaped green blades, known to 

 botanists as prothalli (Fig. 154). The prothallus is the 



