348 



GENERAL MORPHOLOGY OF PLANTS 



along on the ground by the wind. With the advent of rains 

 it expands and becomes green and fresh. It is often sold in 

 the markets because of this curious habit. 



Fig. 331- Fig. 332. Fig. 333. Fig. 334. 



Selaginella with three Fruiting spike, Large spor- Small spor- 



fruiting spikes. (Sela- showing large and angium. angium. 



ginella apus.) small sporangia. 



517. The fruiting spike or cone of Selaginella. The 



sporophylls are usually in four rows over the end of 

 the stems and branches, making a four- sided cone or 



Fig. 335- 



Details of microspore and male prothallium of Selaginella; ist, microspore; 2d, wall removed 

 to show small prothallial cell below: 3d, mature male prothallium still within the wall; 4th, 

 small cell below is the prothallial cell; the remainder is antheridium with wall and four sperm 

 cells within; 5th, spermatozoid. (After Beliaieff and Pfeffer.) 



strobilus. There is a single spore case at the base of each sporo- 

 phyll. A few of the lower ones contain each a few very large 

 spores, one to eight. These are called macrospores * or mega- 



* The sporangia which produce the macrospores are called macrospor- 

 angia or megasporangia, while those which produce the microspores are 

 micros porangia. 



