38 The Botanical Gazette. [February, 



OSMUNDACEiE. — The Osmundaceae differ in several respects 

 from the true leptosporangiate ferns, seeming to connect the 

 latter, to a certain extent, with the Marattiaceae, and perhaps 

 with the Ophioglosseae. An examination of sections of the 

 root-tips shows that the almost mathematical regularity that 

 prevails in the segmentation of the apical cell of the Lepto- 



sporangiatae and Equisetum is here very much less evident. 

 Bower 1 states that in O. regalis there may be a single apical 

 cell of the same form as in the leptosporangiate ferns, but that 

 it never shows the same regularity in its segmentation, and 

 that it may be replaced by two or three initial cells, or a single 

 four-sided pyramidal initial. In Todea barbara 2 (also one of 

 the Osmundaceae) he found usually four similar initial cells, 

 and in no case a single one, although Van Tieghem and 

 Douliot 3 ascribe to this species a single apical cell of the or- 

 dinary fern-type. 



Of the two species investigated by me, O. cinnamomea ap- 

 proached, on the whole, more nearly the forms described and 

 figured by Bower; O. Claytoniana resembled more the ordin- 

 ary fern-type in the regularity of the segmentation of the 

 apical cell, although this seems to be regularly a four-sided 

 pyramid, instead of three-sided as in the other true ferns. 



Osmunda cinnamomea. — This species seems to correspond 

 in many respects with O. regalis. The roots are stout, 

 and sections, either transverse or longitudinal, show the cells at 

 the growing-point to be very large, with correspondingly large 

 nuclei, but relatively little protoplasm. In all specimens ex- 

 amined, there appeared to be a single initial cell, but owing 

 to the large size of the young segments, it was not always 



easy to determine positively that this was the case: but a 



careful examination of the sections led to the conclusion that 

 all the cells were traceable to a single apical cell. 



The apical cell, seen in profile, is more or less regularly 

 triangular (fig. 1), but may be truncate at the base. In all 

 the transverse sections examined, this cell appeared nearly 

 square, so that the normal form of the apical cell in this spe- 

 cies appears to be a four-sided pyramid. In transverse sec- 



1 L c, p. 310. 

 *L c, p. 314. 



,oa7 an 7 ieghem l^lf ^Origine des Radicelles, Ann. des. Sa. Nat. (Bot.) 

 1888. vol. vm, pp^ 378 380. These authors state that all the Osmundacea. ex- 

 amined by them have a single apical cell, essentially like that of the other ferns, 

 but their accounts are very brief. 



