METHODS 



35 



of spore-division. Farmer [i] has given a full description of the nucle.ir 

 division in the spore mother-cells of P. decipiens, where he describes a 

 quadripolar spindle. A similar condition has been noted in Calyculcvria 

 radiculosa (Campbell [2]) ; but in Pallavicinia radiculosa (Fig. 21) and 

 P. Levieri, which were the only species in which division-stages were en- 

 countered, there was no certain evidence of the formation of a quadri- 

 polar spindle. As usual in the Jungermanniales, the s,pore mother-cells 

 are deeply four-lobed. 



The full-grown sporophyte in P. Zollingeri is about 3.5 cm. in height, 



Fig. 21. 



A. Upper part of the capsule of Pallavicinia radiculosa, showing first stages of 



division in the spore mother-cells. 

 B-E. Stages in the mitosis of the spore mother-cells in P. radiculosa, x 640. 



F. Spore mother-cell of P. Zollingeri, x 640. 



G. Spore mother-cell of P. Levieri, x 640. 



H-J. Ripe spores and part of an elater of P. radiculosa. 



