METHODS 



37 



ends. The elaters have two spiral bands. The one figured, which 

 measured 150^1 in length, was somewhat shorter than the majority of 

 them. 



The mature sporophyte of P. radiculosa differs from that of P. 

 Zollingeri in its shorter seta, which, according to Schiffner [1], is only 

 15-20 mm. in length. The capsule, however, is much longer than in P. 

 Zollingeri, but almost perfectly cylindrical in form, scarcely exceeding 

 in width the seta (Fig. 23, D). As already stated, also, the apex is 

 conspicuously pointed. It opens in the same way, by four narrow valves, 

 united at the apex. Except at the pointed apex, the wall of the capsule 

 is composed of three layers of cells, of which the outer one has the cell- 

 walls uniformly thickened, and dark colored. The markings on the ripe 

 spores form a network of delicate ridges, much like those in Fossom- 

 bronia, but quite different from those found in Pallavicinia Zollingeri 

 (Fig. 21, I, J). The ripe spores are 12-150. in diameter, and the elaters 

 often measure about 2250. in length. 



Fig. 23. 



Sections of the capsules of P. Zollingeri, A; P. Levieri, B 



losa, D. B and D are not fully grown. 

 A-C, x 18; D, x 10. 



P. indica, C ; P. radicu- 



Spore Division 



Long before any sign of the final nuclear division in the spore- 

 mother-cell can be seen the cell becomes deeply four-lobed, as in all 

 Jungermanniales. The mother cell in P. Zollingeri (Fig. 21, L), is 

 decidedly larger than in P. radiculosa, but its nucleus is smaller. Traces 

 of what looked like the quadripolar spindle described by Farmer in P. 



