62 



PRACTICAL BOTANY 



trorse (turned inward), when it faces the pistils, as in 

 Magriolia (Fig. d). 



The VERSATILE ANTHER is nsuallj introrse (turned to- 

 ward the axis of the flower) — rarely extrorse. 



The CONNECTIVE is often inconspicuous, or even want- 

 ing, so that the anther-lobes are in close contact. Some- 

 times it outruns the. anther and tips it with an appendage, 

 as in Magnolia^ Liriodendron^ Violet^ Asariim, etc. 



113. xVt maturity, the anther-cells open, or become 

 dehiscent^ to discharge the pollen. There are tJrree modes 

 of dehiscence — namely, ^, the valmdcw — that is, the split- 

 ting open by two lateral, longitudinal lines, one on each 

 lobe of the anther (Figs./*, g) ; h, the porous, in which the 

 cells open by a pore or chink at the apex of the lobe (as 

 in Pyrola^ Fig. h\ and each lobe is sometimes prolonged 

 into a tube, as in Yaccini'inn j c^ the opercular ^ in which 

 each cell opens by a lid, which, as though attached to the 

 apex by a hinge, turas upward like a trap-door, as in 

 Berberis (Fig. i). The commonest mode of dehiscence is 

 the valvular. 



Cut XI. 



114, The POLLEN, when examined under the micro- 

 scope, is found to consist of grains, generally globular or 

 ovoid, sometimes triangular or polyhedral, etc., but all 

 alike in the same species. Each pollen-grain is a mem- 



