?14 PHYTOTOMY. 



by their ripening, but that they have the same size in blos- 

 soms that are not yet evolved as at a later period. 



We are still destitute of any exact information respecting 

 the manner in which the antherae are connected with the 

 filaments, or in what w^ay the opening of the antherae takes 

 place. Meanwhile we observe in a great many plants, in the 

 Irideae, the Laurels, in Jsarnm, and Stratiotes, that the an- 

 therae cling to the side of the filaments in such a manner, 

 that these latter bodies, in some degree, overtop them. In 

 most cases, the antherae either lie horizontally, or swing on 

 the points of the filaments, or these latter parts pass into the 

 substance of the anthera?. Very fine sap-vessels extend from 

 the points of the filaments into the anthera?, and conduct 

 nourishment to them. 



The ripening of the antherae, like the ripening of the fruit, 

 seems to be a kind of desiccation. Although sufficient sap be 

 supplied, it ceases to be taken up. The partitions of the 

 cells become thinner and drier. The cavities, in which the 

 pollen is lodged, press it outwards by means of their elasti- 

 city, and when the extenuated and dried partitions of the 

 cellular texture do not yield, they are rent by force. 



This tearing open, or bursting of the antherae, however, 

 takes place according to fixed and secret laws of nature. The 

 antherae of Solanum^ Galanthiis, Calectasia (R. Brown), open 

 at their summits. In Galeopsis this opening takes place by 

 means of a fringed flap. The antherae of the Syngene- 

 sious plants open longitudinally, each into two compartments. 

 The antherae of the Cucurbitaceae open in winding lines. 

 The antherae of the Laurels burst from the lower to the upper 

 surface, as also those of Epimedmm^ and of Leontice. The 

 antherae of Triglochin open around the circumference, and 

 those of Bros'wiiwi open in a circle which surrounds the 

 middle of the body. We have already noticed, that in flowers 

 which have nectaries, this opening of the anthera? corresponds 

 with the position of the nectaries^ (i531.) 



335. 



If we attend to the pollen, as it appears in most plants, we 

 perceive it to have diff'erait forms in the different families. 



