628 MOSSES AND FERNS 



leaf grows quite rapidly, and soon ruptures the overlying tissues, and 

 appears on the outside of the root. It develops a vascular bundle 

 which joins directly with that of the primary root. 



The stem-apex consists of a shallow mass of tissue with a conspic- 

 uous apical cell, but no indications of any vascular bimdles, and 

 throughout the life of the sporophyte there are no cauline bimdles, the 

 whole vascular system being composed of the united leaf and root traces. 



P. 243. The writer's later studies on Botrychium make it probable 

 that, as in Ophioglossum, there is no proper stele in the stem of Botry- 

 chium, but that all of the vascular tissue of the axis belongs to the 

 leaf-traces and roots. (See Campbell (33).) 



P. 243. Fourth line, for epibasal, read hypobasal. 



P. 244. Lyon (2) found in B. ohliquum a well-marked suspensor, 

 and Lang (9) states that a suspensor is also developed in Helmintho- 

 stachys. The early development of the latter is only imperfectly 

 known, but to judge from later stages (Campbell (33) ), it is more like 

 Botrychium than like Ophioglossum. 



For a detailed account of the development of the vascular system 

 in the young sporophyte of the Ophioglossaceae see Campbell (33). 



P. 245. A full account of the general morphology of the Ophio- 

 glossales has been given by Bower (22). 



P. 245. The genus Ophioglossum has been divided into three sub- 

 genera, perhaps better considered as distinct genera. Euopkioglossum 

 includes the great majority of species, Cheiroglossa has but one species, 

 O. palmalum, while Ophioderma has three : O. pendulum, 0. simplex, 

 and O. intermedium. 



P. 248. The apical cell in O. Moluccanum and 0. reticulatum is 

 either a three-sided or four-sided prism, the apex of which is smaller 

 than the base. 



P. 250. In 0. Moluccanum, and probably in all species of Ophio- 

 glossum, the whole vascular system of the adult sporophyte (except 

 the root) is made up of the leaf traces, which join so as to make a large- 

 meshed hollow cylinder. There is no proper cauline stele. 



The bundle from each young leaf can be traced to a junction with a 

 root-stele, and from the point of junction it extends through the tissue 

 of the axis, running almost horizontally until it joins the trace from 

 the next older leaf. In this way is built up the open, large-meshed 

 vascular cylinder. So far as could be determined, in O. Moluccanum 

 only one root is formed for each leaf. The tissues of the root-base are 

 continued upward to connect with the young leaf, and downward to 

 join the stele from an older one. 



