48o MOSSES AND FERNS chap. 



These observations have not yet, however, been confirmed by 

 other observers. 



The differences between PJiylloglossuvi and Lycopodimn do 

 not seem sufficient to warrant the establishment of a separate 

 family, the Phylloglosseae, as Bertrand proposes. 



The PsilotacecB 



The Psilotacese include the two evidently related genera 

 Psilotinn and Tmesipteris, the former with two species,^ the 

 latter with but a single one. All the species are tropical or 

 sub-tropical, Psilotuni being found in all the warmer parts of 

 the world ; but Tmesipteris is confined to Australia, New 

 Zealand, and parts of Polynesia. The prothallium is quite 

 unknown in both genera, but the development and anatomy 

 of the sporophyte of both are now pretty well known. The 

 sporophyte,- which in its mature condition is quite destitute 

 of roots, grows either upon earth rich in humus {^Psilotum 

 triguetruni), and is evidently more or less saprophytic, or 

 it may be an epiphyte. Tviesipteris grows upon the trunks 

 of tree-Ferns, and Bertrand states that it is a true parasite, 

 which, however, like Viscinn or Phorodendron, has not entirely 

 lost its chlorophyll. The plant always consists of two parts, 

 a lower portion consisting of branched root-like rhizomes, which 

 take the place of roots, and aerial green branches which ramify 

 dichotomously. The branching is especially marked in 

 Psilotuni, much less so in Tmesipteris. The leaves are small 

 and scale-like in Psilotum, larger and lanceolate in Tmesipteris. 

 The sporangia (or synangia) are bilocular in the latter, trilocular 

 in Psilotum, and in both cases borne upon a small bilobed 

 sporophyll. 



The development of the sporophyte has been carefully 

 studied by Solms-Laubach,^ who discovered that it multiplied 

 rapidly by means of small gemmae (Fig. 251, k) produced in 

 great numbers upon the subterranean shoots. These buds or 

 bulblets are small oval bodies, but one cell in thickness, and 

 showing usually a definite two-sided apical cell. Their cells 

 are filled with starch, and they sometimes remain a long time 



^ Baker (2). - Bertrand (i, 2); Solms-Laubach (1); Bower (15). 



' Solms-Laubach (i). 



