THE PTERIDOPHYTES. 



199 



Search among the rhizoids for spherical antheridia. 

 Draw. It is possible that antherozoids will be found 

 swimming in the water. These are spirally coiled organ- 

 isms, having a number of cilia at the small end ; a spheri- 

 cal body is often seen attached to the larger end. The 

 antherozoids swim to the canal of the archegonium, effect 

 an entrance, and fertilize the egg cell. (See Fig. 110, A 

 and _B.) The egg cell now develops by successive cell 



126 



FIG. 126. The same as Fig. 125, somewhat farther advanced. (After 



Suminski.) 

 FIG. 127. The same as Fig. 126, but the protonema has now developed into a 



young prothallium. A fully developed prothallium is shown in Fig. 110. 



(After Suminski.) 



divisions, and produces a new Fern plant with rhizome, 

 roots, and frond. The new plant remains attached to the 

 prothallium for a time, but finally becomes separated and 

 lives as an independent plant. 



References for Reading. Sedgwick and Wilson's " Biology," pp. 

 105-155; Parker's "Elementary Biology," pp. 344-362; Bidgood's 

 "Elementary Biology," pp. 112-144; Goebel's "Classification of 

 Plants," pp. 189-245; Vines' "Text-Book of Botany," pp. 372-415; 

 Bennett and Murray's " Cryptogamic Botany," pp. 10-95, 119-124; 



