204 



THE MARATTIALES 



MACROGLOSSUM. 



This represents a new genus of Marattiaceae, the one species of which, M. alidee 

 Copeland, has recently been described (Copeland I). It is a large fern from Borneo, 

 and is evidently related to Angiopteris, from which it differs mainly in its simply 

 pinnate leaves, which may reach a length of about 3 meters (see Copeland 1, plate V). 



TISSUES OF THE MARATTIACE^. 



There are often present upon the leaf bases of the Marattiaceae peculiar lenticel- 

 like structures to which German writers have given the name "Staubgriibchen." 

 These arise beneath the stomata, and form small cavities whose peripheral cells 

 become detached and dried up, forming a dust-like powder. 



Rod-shaped bodies, mainly composed of cal- 

 cium pectate, are of common occurrence in the 

 intercellular spaces of the tissues of the Marat- 

 tiaceae. Siliceous deposits and crystals of calcium 

 oxalate have also been observed in Angiopteris 

 (see Bitter 1). 



The elements of the vascular bundles are much 

 like those in the bundles of the ordinary ferns. The 

 tracheary tissue is composed mainly of scalariform 

 elements, and the sieve tubes have numerous lateral 

 sieve plates, like those of the other ferns. Hill and 

 Farmer have noted a slight secondary formation 

 of wood in Angiopteris, somewhat similar to but 

 much less marked than that in the stem of Boirych- 

 lum virginianum (see Hill I, Farmer 3). 



THE SPOROPHYLL OF THE MARATTIACE^. 

 The Marattiaceae differ most strikingly from 

 the Ophioglossaceae in the character of the sporo- 

 phylls. In all of the living Marattiaceae the sporan- 

 gia or synangia are borne upon the lower surface Fig. i^.-ArchangiopterU hemyi (after Christ 

 of the leaves, which usually are not at all different ^^^ Giesenhagen). 



from the sterile ones. In Dancea (fig. 189) the sporophylls are decidedly contracted 

 and the very large synangia almost completely cover the lower surface of the leaflets, 

 but in the other genera the sporophyll is not at all contracted and much the greater 

 part of the leaf surface is free (figs. 182, 184, 185, 188). 



Kaulfussia (fig. 188) differs most from the other genera, the very peculiar cir- 

 cular or rarely oval synangia being scattered apparently without any definite order 

 over the whole lower surface of the leaf. In Dancea the elongated synangia, which 

 lie over the veins, extending from the midrib nearly to the margin of the leaflet, are 

 crowded so that they leave very little of the surface free. In Marattia and Angiop- 

 teris the synangia lie over the veins as they do in Dancea, but they are very much 

 shorter and are formed near the margin of the leaflet, within which they form a 

 single hne which occupies only a very small part of the leaf. Archangiopteris, except 

 that the synangia are very much longer, agrees closely with Angiopteris. 



No proper indusium is present in the Marattiaceae, although very commonly 

 about the base of the synangium there are found a few hairs or scales which have 

 sometimes been considered to represent an indusium. In Dancea there is a growth 

 of tissue between the elongated synangia, which grows up into a sort of ridge the 



