58 DUDLEY MEMORIAL VOLUME 



of these nuclei moves to each lobe of the mother cell, but generally remains 

 near the center of the .cell, so that the four resulting nuclei are quite close 

 together (Fig. 11, M). 



Not all of the spore mother cells, however, behave in this fashion, but 

 sometimes after the first division of the chromosomes a conspicuous bi- 

 polar spindle of the usual form was observed. (Fig. 11, K). Later two 

 resting nuclei were seen with a cell-plate between them. (Fig. 11, L). These 

 secondary nuclei then divided again, each developing another bi-polar 

 spindle, these secondary spindles sometimes lying at right angles to each 

 other. (Fig. 11, J). 



After the nuclei have assumed the resting condition cell walls are 

 formed, simultaneosuly extending inward from the indentations between the 

 lobes and completely dividing the mother cell into its four component parts, 

 the young spores. 



The ripe spores (Fig. 12, F, G) possess a thick membrane, which in 

 sections shows two well-marked parts, an inner uniform layer and a thick 

 outer one provided with rounded knobs, which give it a very characteristic 

 appearance. The color of the spore is dark purple-brown, like the thicken- 

 ings upon the cells of the capsule wall. It is probable that immediately 

 adjacent to the spore cavity is a thin membrane (intine) of cellulose, but 

 this was not specially investigated and did not show clearly in the sections 

 that were examined. The nucleus of the spore is rather small but fairly 

 conspicuous. 



The elaters (Fig. 12, C, D and E) show a good deal of variation. 

 They are sometimes very much attenuated, with the spiral bands almost 

 obliterated at the ends, suggesting the elaters of Makinoa, where the spirals 

 are present only in the mid-region of the elaters. More commonly, however, 

 they taper more gradually and the double spiral extends to the end. Con- 

 siderable difference in size may be noted (Fig. 12, E). While no basal 

 elaterophore is present, occasionally some of the elaters at the base of the 

 capsule seem to be attached at one end and suggest a rudiment of such an 

 elaterophore, as is said to occur in the other species of Calycularia. 



The surface markings of the spore in Calycularia radiculosa are strik- 

 ingly different from those of Pallavicinia whether of the section Morkia or 

 Blyttia. In Pallavicinia (See Fig. 12, K, L) the surface markings have 

 the form of a network of delicate ridges, such as also occur in Fossombronia. 

 This marked difference in the character of the spores, together with certain 

 other differences, might be considered to be an objection to uniting Caly- 

 cularia radiculosa with the genus Morkia. 



The structure of the capsule wall of Calycularia radiculosa, according 



