142 MORPHOLOGY AND LIFE HISTORY 



tion. Does their distribution on the rhizome 

 bear any constant relation to the point of origin 

 of the aerial branches? 

 4. Make drawings showing all points observed under 



c, 1-3. 



D. Asexual Reproduction: 



1. Vegetative Propagation. 



(a) Describe the possibility of the multiplication 

 of new individuals by isolating pieces of the 

 rhizome. 



2. Reproduction by Spores. 



(a) Sketch the strobilus or cone (X 3). 



(b) Make a cross-section of the cone at about one- 

 third of the distance from the apex, and observe 

 the central axis, and the manner in which the 

 sporophylls are borne. 



(c) Carefully dissect off a sporophyll, and observe 

 (i) its stalk; (2) its peltate (shield-like) top; 

 (3) hanging from the under surface of the 

 shield, the sporangia. How many sporangia 

 on each sporophyll? Examine several sporo- 

 phylls to see if the number of sporangia is 

 constant. Describe the dehiscence of the 

 sporangia. 



(d) Examine the spores under the microscope. 

 Can you detect more than one size; i.e., is 

 Equisetum a homosporus or a heterosporus 

 plant? 



(e) Describe the appendages (elaters), of the 

 spores. How many on each spore? They are 

 formed by a modification of the outer coat of 

 the spore. Observe their behavior when 

 breathed on at frequent intervals. 



(/) While the spores are morphologically homo- 



