XIII 



EQUISETINE.^ 



455 



In the connecting spindles is formed between each pair of 



ccn. D. 



Fig. 24c. — Development of the spores. A, Group of four sporogenous cells, x6oo; B, section of a 

 single sporogenous cell, just before the first division of the nucleus, x 1200 ; D-H, successive stages 

 in the division of the nuclei, X 1200 ; cen, centrospheres ; nu, nucleolus. 



nuclei a cell plate, which here soon develops into a definite 

 cellulose membrane, and the spores separate completely. 



