60 VEGETABLE ORGANOGRAPHY. 



The position of the anthers with regard to the pistil 

 ought also to be observed. The most frequent and natural 

 ease is that where the anther, whatever be its mode of 

 attachment, has its back towards the outer, and its cells 

 on the inner side of the flower : it is this that is meant 

 whenever it is not expressed to the contrary in descrip- 

 tions; when it is necessary to express it, we say that 

 it is Introrse (introrsa, antica). In some plants it is 

 placed in the contrary way, so that its back faces the 

 pistil, and the cells open towards the calyx ; this kind of 

 anther is called Extrorse {extrorsa, postica) : we observe 

 it very clearly in certain adnate anthers, such as those of 

 the Magnoliaceas, or in those with flat filaments, as in 

 Iris ; but when the filaments are slender, or when the 

 anthers are erect or versatile, the observation of their 

 true direction presents some difficulties, because it often 

 happens that the filament is so twisted as to place the 

 anther in a situation different from its natural one ; 

 thus we may often mistake their, true position in the 

 Ranunculaceae. 



The form of each of the cells is sometimes round, 

 and then we say of the anther that it is Didymous : 

 more frequently oval; sometimes long or linear; this 

 last case especially takes place in adnate anthers, as 

 those of the Magnoliaceas : when these cells are erect, they 

 present two convex bands, separated by a rectilinear 

 furrow: sometimes they are at the same time adnate, 

 linear, and more or less curved, and then they present 

 inequalities and curves of a remarkable appearance ; we 

 see this in the Gourd, in Durio, Eriodendron, &c. ; these 

 anthers are called Anfractuose. Those with round 

 cells frequently open by a transverse fissure, those of a 

 linear form by a longitudinal one, and oval anthers 

 present all kinds of dehiscence. 



The colour of the anther is often yellow; sometimes 



