382 On the Reproductive Organs of Pilularia globulifera, 



length, by the slender palpi of which the terminal joints are elon- 

 gate, by the second joint of the legs being more than twice the 

 length of the first, and by the oviferous legs of which the three ba- 

 sal joints are stouter than the fourth, and this again is much stouter 

 than the others, which form a sort of filiform appendage. 



Fig. 9. Nymphon gracile, nat. size; 10, the same magnified ; 11, 

 the head still more highly magnified and seen from below; 12, an 

 oviferous leg highly magnified. 



VIII. — Remarks on the Reproductive Organs of Pilularia globuli- 

 fera, and the Globules of Char a vulgaris. By Mr George 

 Dickie. 



Pilularia globulifera belongs to the natural order Marsile- 

 aceae; the essential characters of which are, according to Lindley, 

 " creeping plants ; leaves petiolate and divided, (or petioles desti- 

 tute of lamina,) rolled up in vernation. Reproductive organs in- 

 closed in leathery involucres, and of two kinds, the one consisting of 

 membranous sacs, containing a body or bodies which germinate, the 

 other, of similar sacs, containing loose granules." Sir W. J. Hooker 

 gives the following definition of the genus Pilularia : " Involucres 

 solitary, nearly sessile, globose, coriaceous, four-celled ; each cell con- 

 taining two different kinds of bodies; (anthers ? and pistils?") The 

 larger of these have been considered as thecae by Brown, Hooker, 

 Greville, and others. Annexed is a magnified representation of one 

 of the thecae. The smaller bodies are more numerous 

 than the others, and their shape is simply orbicular ; 

 both consist of a tough white membrane. Each 

 of the larger bodies is contained in a reticulated 

 transparent membrane, the smaller are in clusters 

 inclosed together in a similar membrane. If one of 

 the supposed thecae is ruptured, there issue numerous round tran- 

 sparent particles ; these have been considered as sporules. While 

 engaged in examining the nature of these particles, a zealous and ac- 

 curate observer, Mr Peter Grant, of this place,* suggested to me the 

 propriety of employing chemical tests. I furnished him with speci- 

 mens, and, on examination, he discovered that the supposed sporules 

 were coloured blue by iodine, thus demonstrating that they are grains 

 of fecula or starch. I have observed that along with the fecula there 

 exists a fluid which possesses all the properties of a. fixed oil. 



The small orbicular bodies have been supposed to be analogous to 

 * Aberdeen, 



