Miscellaneous. 139 



The diflFerence is greater in Aglaonema marantcefolia, Schott. 

 The bilocular anther is furnished with a short filament, and the 

 connective does not form a plate. Each cell is divided into two 

 locelli by a thick septum, absorbed beneath the terminal pore where 

 the locelli communicate. The inner wall of each locellus is lined 

 throughout with a strong layer of perpendicular fibrous cells : hence 

 the quadrilocular structure of the anther. The fibrous layer is 

 produced upon the outer walls up to the orifice, where it is covered 

 directly by the epidermis. 



Hence there is no necessary correlation between apicilar dehis- 

 cence and the absence of fibrous cells. The presence or absence of 

 these is a character of more constancy and of a higher order than 

 the mode of dehiscence. Thus in the Aroidese we pass by insensible 

 gradations from Richardia, &c., in which the apicilar dehiscence is 

 most strongly marked, through Arum and Dracunculus, to rimate 

 dehiscence, either transverse (Arisarum) or longitudinal (Calla, 

 Anthurium, &c.), whilst the fibrous layer is still strongly developed; 

 and this is further seen from the complete absence of these cells in 

 Lycopersicum (where the dehiscence is longitudinal), and their nearly 

 complete absence in Solarium (where it is apicilar). Moreover api- 

 cilar dehiscence is by no means common to all the genera of the 

 families in which M. Chatin has ascertained the general absence 

 of the fibrous cells : thus the Epacridese open their unilocular 

 anthers by a longitudinal fissure ; among the Ericaceae Leiophyllum, 

 Pieris, and Epigcea, and among the Melastomaceae Mouriria, Meme- 

 cylon, &c., open their bilocular anthers by two longitudinal fissures; 

 lastly, in the Monotropeae the unilocular anthers of Monotropa and 

 Hypopitys open by a transverse fissure, whilst the bilocular anthers 

 of Pterospora have a longitudinal dehiscence ; and yet the fibrous 

 layer is wanting in all these genera. 



M. Chatin has also observed the structure of some abnormal 

 anthers (those of Hypoxis erecta and Pittosporum Tobird), "which 

 are destitute of fibrous cells at the same time that they are empty 

 of pollen, or only contain it in an imperfect state ; these sterile 

 anthers have, no doubt, been seized by an arrest of development act- 

 ing simultaneously upon the tissues of the second membrane and 

 upon the pollen ;" and from this he concludes " that in some plants 

 the stamens of which have undergone an arrest of development, the 

 absence of fibrous cells coincides with the imperfect evolution of the 

 pollen." The author's observations upon Ranunculus Ficaria show 

 that something very different may be the case. The anthers of the 

 bulbiferous variety of this species produce no pollen, and this is the 

 sole cause of the sterility of the plant. Each anther-cell, divided 

 into two locelli by a septum, has its valve formed of an epidermis 

 thickened by a layer of spiral and reticulated cells which does not 

 extend over the septum or upon the inner wall of the cell formed by 

 the connective, as appears to be generally the case in the Ranunculi. 

 In the interior of each locellus there is a long mass narrowed at the 

 two extremities, formed of several rows of large, polyhedric, colour- 

 less, thick-walled cells furnished with numerous dots; these cells 



