22 Linnean Society. [March 19, 



R. H. Solly, Esq., F.R.S. and L.S. By William Valentine, Esq., 

 F.L.S. 



The author observes, that the involucrum of Pilularia globulifera 

 contains two kinds of bodies, which, however, occupy distinct sacs ; 

 one kind are round, very numerous, and minute, not larger than the 

 460th part of an inch -, they are found principally in the upper part 

 of the involucrum, and are about forty in each sac. The other kind 

 are of an oblong pyriform shape, a little constricted near the middle, 

 with a conical projection at one extremity, and are much less nu- 

 merous, about sixty, and occur singly in each sac ; they are about 

 the 80th part of an inch broad, and have the power of germination, 

 which the former kind do not appear to possess. Both kinds are 

 loose in their sacs, and have an opake, pure white, minutely granular, 

 testaceous covering, and are imbedded in a kind of gelatin, which 

 softens and expands by the action of water, but is not completely 

 dissolved. The larger bodies, the undoubted sporules, after a very 

 slight maceration in water, (less than a minute is sufficient,) are en- 

 veloped by a well-defined covering of gelatinous matter, which be- 

 fore the maceration existed in a concrete state. Further macera- 

 tion does not appear to affect this gelatinous covering, as it remains 

 unchanged long after germination, and gives to the sporule the ap- 

 pearance of having a very delicate transparent border, whose breadth 

 is about the 4th part of the diameter of the sporule. 



The sporule consists of three coats, the outer of which is white, 

 opake, somewhat brittle, more or less incomplete at the conical ex- 

 tremity, but much thickened about the upper third of the sporule, 

 where it exhibits traces of cellularity. The middle coat is mem- 

 branous, elastic, of a light yellowish brown colour, and perforated at 

 the apex of the conical projection which is essentially formed by 

 this coat, the outer coat being gradually lost upon its surface, or in 

 some instances being scarcely continued on to it, in which case the 

 sporule appears truncated, the middle membrane not having sufficient 

 firmness of itself to support the conical form. This conical projec- 

 tion is more or less plicated, and in those instances in which the outer 

 coat is very deficient the middle membrane exhibits lines radiating 

 from the aperture. The third coat, or internal membrane, is similar 

 in colour to the middle, differing from it however in being inelastic, 

 and not being continued into the cone, but forming a short cavity, 

 by passing directly across the base of the cone, at which point it is 

 not in contact with either of the other membranes, and is marked 

 by three lines, which radiate from the centre of the unsupported 

 portion, and indicate a valvular structure to allow of the protrusion 



