r 



1907] BURUNGAME— SPORANGIUM OF OPHIOGLOSSALES 35 



t.- 



Earlier stages 



OPHIOGLOSSUM 



w 



According to Bower, the first indication of the regions from which 

 sporangia are to form is the differentiation along each side of the 

 spike of a band about two cells wide. The cells of this band are 

 distinguished from their neighbors by a greater depth, a difference in 

 arrangement, and diflferences in cell contents. He calls this the spo- 

 rangiogenic band. The cells are for the most part arranged in pairs, 

 but he does not regard this as sufficient evidence of their common 

 origin, for he says that if the cells concerned in forming a single 

 sporangium originate from a single cell, it must be very early in the 

 formation of the spike. Nor did he succeed in distinguishing them 

 at a stage so early as to enable him to trace their origin. At a slightly 

 earlier stage, Goebel figures the band as only in part two cells wide. 

 His figure seems to support his contention that the band becomes two 

 cells wide by the longitudinal anticlinal splitting of the cells of a band 

 but one cell wide. Some of Bower's i 



arrangement of the cells in the band. In these cases, as he clearly 

 points out, it is much less easy to refer the origin of the band to a 

 smgle row of cells. It is not unlikely that the difference of opinion 

 IS due to the recognition of the band at slightly different stages in the 

 growth of the sporangial spike, for it is not unusual for subsequent 

 growth to displace cells so as to render their relationship to one 

 another obscure. Whatever may be the exact mode of origin of this 

 band, the really important point is that sporangia may arise in any 

 part of it, though in fact they do not arise in all parts of it. It is this 

 partial sterilization of a band potentially sporangiogenic throughout 

 on which Bower lays special stress. 



The cells of this sporangiogenic band divide periclinally, sepa- 



& 



primary 



orium 



band 



lorium. Goebel, with whom Campbell 



rmm 



agrees, thinks the archesp 

 claims a unicellular archesporium, but Russow conti 

 cell-complex. From such divergent opinions the tru 

 choose, though it seems not unlikely that the band may 



also 



