3 



1891.J Notes on Osmunda and Botrychium. 41 



that shown in fig. 4, to the inner of the two primary cells 

 into which each semi-segment is divided. 1 (fig. 4, p. c). The 

 plerome-cylinder is much smaller than in O. cinnamomea, 

 and in its mature condition resembles very closely the bundle 

 of the ordinary fern-root, and differs from the investigated 

 species of Osmunda and Todea 2 in the better development of 

 the bundle-sheath and in having the pericambium consisting of 

 but one, or at most two layers. The arrangement of the 

 tracheary tissue, too, is entirely similar to that of the Poly- 

 podiaceai. ' . 



Opiiioglosse.k. — Unfortunately at the time these investi- 

 gations were made, only a very small number of plants of 

 Ophioglossum were obtainable, and the roots of these were 

 not properly prepared for imbedding, the plants having been 

 preserved in ordinary alcohol, so that it was impossible to 

 get satisfactory preparations, and my observations were 

 therefore confined to the two common Botrychia, B. ternatum 

 and B. Virginianum. 



The Ophioglossere have been comparatively little studied, 

 and the investigations that have been made on the roots are 

 not satisfactory. B. ternatum was examined by me some 

 time since, 4 and the results of the paper then published were 

 confirmed for the most part ; but somewhat less regularity in 

 the segmentation of the apical cell was found to exist than 

 there described, and a consequent departure from the ordi- 

 nary fern-type. 



Botrychium ternatum. —The apical cell of this species 

 (fig. 9) is in form quite like that of the Polypodiacea;, but the 

 segments are noticeably larger and remain longer undivided, 

 in which respect they approach the Osmundacea,'. The first 

 division in the young segment (fig. 10) follows the regular 

 rule, dividing it lengthwise into two cells, which are, how- 

 ever, more unequal than is usually the case in ferns, and the 

 subsequent divisions are less definite, although they follow 

 the same general rule. Here, as in the Osmundaceai, the 



1 Van Tieghem and Douliot call attention to the fact, confirmed by the ob- 

 servations recorded here, that the Osmundaceae differ from the other ferns in 

 having the innermost of the two primary cells of the semi-segment smaller, and 

 giving rise directly to the procambium. (1. c. p. •>r , .>.) 



2 De Bary: Comp. Anat. (Eng. translation) p. 3<>4. 



» Holle: Ueber die Vegetationsorgane der Ophioglosseen; Sot. Zeit. t 187;>. 

 4 Campbell. The development of the root of Botrychium ternatum; Bet. 

 Gazette, March, 1881). 



