632 MOSSES AND FERNS 



a very early period a second vascular bundle or stele is formed in the 

 second leaf, and this stele joins the primary axial bundle of the young 

 sporophyte. In DancBa, which was especially studied, a similar 

 single stele is formed in each succeeding leaf, up to about the seventh. 

 Up to this time, except for the steles of the secondary roots, the whole 

 vascular system is built up of united leaf-traces, and there is no cauline 

 stele in the strict sense of the word, although one may speak of the 

 bundle or stele of the stem, as soon as there is a solid central strand 

 formed by the junction of the early leaf-traces. This primary stele 

 never has the character of a true protostele, as the xylems belonging 

 to the component leaf-traces can be clearly recognized, and the com- 

 pound nature of the stele is unmistakable. 



At a later stage, about the time the seventh leaf is formed, there 

 arises a single axial ("commissural") strand, which is really of cauline 

 origin, and the only part of the vascular system which strictly belongs 

 to the stem. The leaf-traces formed subsequent to the appearance 

 of the commissural strand are double. 



In the older sporophyte the vascular system of the axis has the form 

 of an open wide-meshed cylinder ("Dictyostele"), within which is the 

 commissural strand (or strands). 



P. 290. The "meshed zones," are really built up of the very 

 complicated leaf-traces from the gigantic leaves, which sometimes 

 measure 5-6 metres in length. 



P. 291. The statement of HoUe (2), that sclerenchyma is present 

 in the stem of DancBa, was based upon an error, the plant examined by 

 him not being a DancBa, or any Marattiaceous fern. DancEa, like 

 all the other Marattiaceae, has no sclerenchyma in the stem. 



P. 292. For Brebner (2), read (i) ; for Luerssen (7), read (6). 



P. 292. Archangiopteris and Macroglossum, like Angiopteris, have 

 separate sporangia. 



P. 297. An examination, by the writer, of sections of sporangia of 

 several forms of Angiopteris, showed a structure corresponding to that 

 given by Professor Bower. 



P. 298. In Macroglossum (Campbell (36) ) the elongated sori are 

 separated by an elevated ridge, not unlike that found in Dancea. 



P. 298. Probably the four sub-families given may better be 

 considered as families, viz., Angiopteridacese, Marattiaceae, Kaul- 

 fussiaceae, Danaeaceae. The Angiopteridaceae now includes also 

 Macroglossum. • 



P. 299. KaulJussia = Christensenia. A second species, C. Cumin- 

 giana, has recently been discovered in the Philippines. 



