256 



THE FLOWEB. 



proper filament, and bearing an anther-cell at each end. In a 

 few species, the two anther-cells are nearly alike ; in more, the 

 lower one is imperfect, as in Fig. 510" ; in more, it is abortive 

 or wanting altogether, as in Fig. 510*. Then, in the related 

 Californian genus Audibertia, the lower half of this connective 



fs reduced to a short tail, as shown in Fig. 511, or even in 

 most of the species to so minute a vestige that, except for these 

 transitions, the stamen might be supposed to consist of a simple 

 filament, with an interruption like a splice in the middle, and 

 surmounted by a one-celled anther, as shown in Fig. 511*. In 

 Rosemary, the continuity is complete, although a minute reflexed 

 tooth sometimes indicates the junction. 



470. Pollen, the product of the anther, is usually a powdery 

 substance, which when magnified is seen to consist of separate 

 grains, of definite size and shape, uniform in the same plant, 



but often very different in different species or families. The 

 grains are commonly single cells, globular or oval in shape, and 

 of a yellow color. But in Spiderwort they are oblong ; in the 



FIG. 508-511. Anthers, with upper part of filament, of several Labiatse. 608. Of 

 Monarda. 509. Of a Calamintha. 510 Of two species of Sal via, with long and slender 

 connective, the upper fork of which bears one anther-cell ; the lower in a (from Salvia 

 Texana), bearing the other cell in an imperfect condition ; in b (from S. coccinea), bear- 

 Ing none at all. 511. a. Same of Audibertia grandiflora, the lower fork of the connec- 

 tive reduced to a naked spur ; b, from A. stachyoides, in which this lower fork is nearly 

 wanting, and the upper is in a straight line with the filament which it seems to 

 continue. 



FIG. 512-515. Forms of pollen: 512, from Mlmulus mowhatus; 513, Sicyos; 614, 

 Echinocystis; 515, Hibiscus. 



