346 THE SEA SHORE 



and the fruit is developed in the axils of the leaves that form the 

 terminal cones of the fertile branches. 



The above are all the principal divisions of the flowerless plants, 

 and we have now to note the general characteristics of the 

 Phanerogams. The chief of these is, of course, the possession of 

 flowers as reproductive organs ; and although it is not convenient 

 to give a full description of the flower at the present time, it will 

 be necessary to say a little concerning it in order that we may be 

 able to grasp the broad principles of classification. 



A flower, in its most complex form, consists of parts arranged 

 in four whorls arranged concentrically. The first and second 

 whorls, commencing from the outside, usually consist of leaf-like 

 bodies, united or distinct, and are called respectively the calyx and 

 the corolla. The third whorl consists of stamens, which are the 

 male reproductive organs of the plant, and each stamen consists 

 essentially of a case the anther in which are formed a number 

 of little pollen cells. When the anther is ripe it opens, thus 

 liberating the pollen, so that it may be dispersed by insects, by 

 the wind, or by other mechanical means. The remaining whorl 

 constitutes the pistil, which is generally made up of parts (carpels) 

 arranged round a common centre, and each surmounted by a 

 stigma adapted for the reception of the pollen cells. This portion 

 of the flower contains the ovules, enclosed in a case called the 

 ovary, and is, therefore, the female organ of the plant. When the 

 ovules have been fertilised by the pollen, they develop into seeds, 

 each one of which contains an embryo plant ; and the ovary itself, 

 ripening at the same time, develops into the fruit. 



Such is the general description of a flower in its most complex 

 form, but it must be remembered that one or more of the whorls 

 named above may often be absent. Thus, calyx or corolla, or both, 

 may not exist; and the male and female organs may be developed 

 on separate flowers of the same plant, or even, as is frequently the 

 case, on different plants of the same species. In the latter instance 

 the flowers are spoken of as unisexual, those bearing the stamens 

 being the staminate or male flowers, and those bearing the pistil 

 the pistillate or female flowers. 



The Phanerogams are divided into two main groups, the 

 Gymnosperms and the Angiosperms. In the former the ovules are 

 naked, no ovary or seed-case being developed. The pollen, carried 

 by the wind, falls directly on the ovule, and then develops a tube 

 which penetrates to the nucleus of the ovule, thus fertilising it. 



