OP ARTS AND SCIENCES. 215 



The eiDitlermal layer is not ruptured and curled back as in R. glanda- 

 Iceformis (Fig. 1), but the individual cells retain their original posi- 

 tions, and the mycelium makes its way outward between them, curling 

 up and reflecting only the heavy cuticula. 



The hymenium consists of short paraphyses, which are closely 

 packed together, each paraphysis having two or three transverse par- 

 titions. The young heads appear on a level with the summits of the 

 paraphyses, and seem to be connected with the deeper mycelium by 

 several stalk-cells. The older heads rise far above the paraphyses, 

 and are supported by what appears to be one of the stalk-cells very 

 greatly elongated. What has happened to the other stalk-cells, or 

 whether the head was ever connected with more than one of these 

 cells, is uncertain. 



The matured head in cross-section (Fig. 18) shows a structure quite 

 different from that of R. glandidceformis. The spores are throughout 

 unilocular, and, although in the centre of the head each one is sub- 

 tended by a cyst-cell, on the sides one large cyst-cell underlies two or 

 even three of the spore-cells. The stalk is attached to one or two of 

 these small central cyst-cells, and upon the application of a solution 

 of potassic hydrate the larger lateral cysts swell into the balloon-like 

 form seen in Figs. 17 and 19, and so hide the stalk that it appears to 

 attach itself to the spore-mass independently of any cysts. The stalk, 

 which becomes greatly elongated as the head matures, seems to be 

 simple, and not compound as in R. glandidceformis. 



Of all the species which we have examined, R. Tndica is the only 

 one in which the spore-cells are persistently unilocular, the stalk sim- 

 ple, and two or three spores often subtended by one cyst-cell. Unfortu- 

 nately, R. aculeifera has not been examined ; but, according to Mr. 

 Cooke, this species also has unilocular spores, and it is therefore proba- 

 ble that R. aculeifera is of the same type of structure as R. Indica. 

 These two species may then be placed in a group contrasted in the 

 three characters already mentioned with R. glandulceformis and its 

 allies. 



Amongst the species closely related to R. glandulceformis is R. gla- 

 bra, K. and Cke. This species was distributed in the Rabenhorst- 

 Winter, Fungi Europasi, Nos. 2624 and 2624 b, upon the leaflets and 

 leaf rhachis of Calpurnia silvatica, E. Mey. The teleutosporic heads 

 occur in clusters scattered over the leaflets. These clusters are indi- 

 vidually quite small compared with those of R. glandulceformis, and, 

 unlike the latter, they are never placed so closely together as to give 

 the appearance of covering the general surface of the leaflet. Each 



