175 



sibly its identity with some of the forms associated under the 

 name 0. inoluccanuiu, by Raciborski. There was, however, no 

 way of certainly identifying the young pkints, as all the species 

 grow together so that it is by no means certain that all the 

 embryos or yomig sporophytes described, really belong to the 

 same species. However, they all agree very closely, and it is 

 doubtful whether there is any great difference among them. 



0. moluccanum and the forms associated with it differ strik- 

 ingly from both 0. vidgatum and 0. pendulum. As Mettenius 

 correctly showed in 0. pedunculosum, the first organ to be 

 developed is a leaf (cotyledon) which soon pierces the earth and 

 appears as a green foliage leaf above its surface. This primary 

 leaf is continued directly into the primary root, (Fig. 132) but 

 no stem apex is developed nor is any sheath formed about the 

 leaf base in the young sporophyte, which consists simply of 

 leaf and root. The latter often penetrates for some distance 

 into the prothallial tissue before it emerges so that the central 

 portion of the young sporophyte is surrounded by a sheath 

 formed by the prothallial tissue (Fig. 135). A longitudinal 

 section of the sporophyte (Fig. 135) shows that the tissues of 

 the leaf are continued directly into those of the primary root. 

 A single axial vascular bundle traverses the whole of the young 

 sporophyte without interruption, and there is no evident 

 boundary between the tissues of the leaf base and those of 

 the root. The central region of the embryo is somewhat broader 

 and its outer cells slightl}'^ enlarged, but no clearly marked foot 

 can at this time be recognized. The strictly bipolar character 

 of the young sporophyte and the way in which it perforates 

 the gametophyte resemble most nearly corresponding stages of 

 Equisetum and the Marattiaceae. Lyon's recent note on Botrij- 

 chluiii ohliquum is interesting in this connection, as there is a 

 similar bipolar arrangement of leaf and root in that species. 

 The sporophyte in the latter also perforates the prothallium much 

 as is the case in the Marattiaceae, and there is no clear develop- 

 ment of a foot. Lyon, however, states that in this species there 

 is a suspensor, and figures this in the young sporophyte. If 



