THE STAMENS. 119 



outer whorl is the most subject to this modification, and also to the transformation into 

 petals. Its colour is usually white; but in the Evening Primrose and the Fuschia it is 

 gaily coloured. 



The anther is essential only so far as it protects the pollen, which is the male essence 

 in the plant. It consists of a series of cells, which are attached to the top of the fila- 

 ment in three recognizable modes. First, when the base of the anther- case is connected 

 with the apex of the filament (innate, Fig. 229) ; secondly, when the union is at the 

 back of the anther (adnatc, Fig. 231) ; and, thirdly, when it is so slightly attached, as 

 in grasses, that it can swing freely in almost any direction (versatile), Fig. 237 B. This 

 and other facts will be better understood by a reference to the analogies of the anther ; 

 for as that organ is the modified lamina or blade of the leaf with its edges so folded that 

 it can inclose contents, it would evidently be expected that in its normal state it should 

 be attached to the filament or petiole by its base. 



This view of its construction will also lead us to infer that there are two cells (one 

 on each side of the midrib), with two points of union viz., one behind, called the 

 midrib, or dorsal suture, and one in front, known as the newly-formed ventral suture. 

 There will also be one line of separation or division viz., that lying between the dorsal 

 and the ventral sutures, called the connective. Such, it is probable, is the normal type 

 of construction of the anther ; but in the extremely modified form in which the leaf 

 thus appears, it is no matter for wonder if the relations of parts should be found much 

 altered. Thus the connective is sometimes absent, and then the anther is one-celled ; 

 and, on the other hand, a new septum arises across each cell, and the organ becomes 

 four-celled ; and this latter, according to the investigations of Schleiden, is the more 

 common form of anther (Fig. 227). 



Its actual construction is best seen at the period of its opening or dehiscence for the 

 expulsion of the pollen, and the precise mode of its rupture has been carefully investi- 



Fig. 227. Fig. 228. 



Fig. 227, representing a cross section of an Anther. A, the connective with the bundle of vessels at 

 a ; B, the halves of the Anther corresponding with the halves of the leaf; d t processes sub- 

 dividing each lateral half, so as to form four loculi or cells. 



Fig. 228. Exhibiting the ordinary mode of dehiscence at a, by longitudinal fissure, leaving the cell 

 open, and some grains of pollen attached , and at 6, the opening by the rupture of the valve or 

 face of the Anther c, which then curves back, as in the Berberry. 



gated. It is certain that the line of rupture runs longitudinally along the ventral 

 suture, and not transversely, except in a few instances, as in the Duck- weed (Lemna), 

 Fig. 226 b, and that the cells open by a separation of two portions or valves, which 



