74 Kansas Academy of Science. 



Subkingdom *IIL* CARPELLATA. Carpellates. 



Carpellate Seed-bearing Plants. 



Plants with flowers containing anthers or ovules, or both. Anthers 

 carrying one, two or four androsporangia, within which pollen (andro- 

 spores) are perfected, are usually located at the summit of stamens (an- 

 drophyls), from which, when mature, the pollen, each spore carrying one 

 or more antherozoids or sperms, escapes through a slit, a pore, a trap-door, 

 a wicket, a window, or other specialized form of dehiscence. Spores de- 

 velop a pollen-tube. 



Ovules (gynosporangia) are situated at the base of a specialized leaf, 

 called a carpophyl or carpel, and are either naked always or for a time on 

 the inner surface of a leaf, or are fully enclosed within a special cavity of 

 the folded leaf. 



Fecundation is effected by pollen (minute androspores bearing motile or 

 nonmotile antherozoids) falling upon an ovule (gynosporangium) within a 

 special chamber on or within a carpophyl (fruit-bearing leaf), germinating 

 there, and passing through the micropyle (little gate) by means of its 

 pollen-tube, which has grown for that special purpose, encounters an egg- 

 cell (gynospore) with which one of the antherozoids fuses, thus producing 

 an embryo. (As to what becomes of the other antherozo-id see Phylum *V, 

 Anthophyta, post.) 



Sporophyte (nonsexual plant) conspicuous, comparatively long-lived, 

 fi.rmly rooted in the earth, normally erect, and spreading its leaves in the 

 air (or water). Bearing flowers, which is preparatory, is a condition pre- 

 cedent to bearing fruit, which is final. 



Gametophyte (sexual plant) very minute and hidden, usually microscopic, 

 totally parasitic on the sporophyte, and retained within the developed ovule 

 until mature; then, having all the food materials stored up about it that are 

 necessary for nursing the young embryo until it has become established as 

 an independent existence by casting its roots into the soil and depending 

 upon its own ability and surrounding resources, the future plant is organized 

 into an independent and self-supporting creation, is separated from the 

 parent plant and undergoes what is called a resting stage, but which is in 

 reality a formative period, during which all the cells are very minutely 

 divided and subdivided, assembled, and organized as required to constitute 

 an orderly arrangement of the interior, in which the entire vegetative por- 

 tion of the future-existing plant for one year is fully organized in miniature, 

 in embryo, awaiting only development. This is the seed, which, when the 

 necessary time for complete organization has elapsed, and the proper and 

 requisite conditions are encountered, germinates and grows into a plant like 

 the parents. The reproductive portion of the plant is not organized in the 

 seed; but is organized toward completion of development of the vegetative 

 portion. 



Thus, every carpellate plant in existence passes through four important 

 periods or stages in its life, namely: 



First. A generative stage, during which the nucleus of a gynospore 

 within an ovule on or in a carpophyl undergoes definite division, and, under 

 certain fixed conditions, becomes impregnated by fusion with it of a gen- 



