SECTION 10.] 



PISTILS. 



109 



tiguous margins of two pistil-leaved grown together. There is every grada- 

 tion between this and the three-celled ovary with the placenta; in the axis, 

 even in the same genus, sometimes even in dill'erent stages in the same 

 pistil (Fig. 335, 330). 



§ 2. GYMNOSPERMOU8 GYXCECIUM. 



313. The ordinary pistil has a closed ovary, and accordingly the pollen 

 can act upon the contained ovules only indirectly, through the stigma. 

 This is expressed in a term of Greek derivation, viz. : — 



Angiotpermou*, meaning that the seeds are borne in a sac or closed 

 vessel. The counterpart term is 



Oymnospermous, meaning naked-seeded. This kind of pistil, or gynoe- 

 cium, the simplest of all, yet the most peculiar, characterizes the Pine 

 family and its relatives. 



314. While the ordinary simple pistil is conceived by the botanist to 

 be a leaf rolled together into a closed pod (30G), those of the 

 Pine, Larch (Fig. 337), Cedar, and Arbor- Vita (Fig. 338, 

 339) are open leaves, in the form of scales, each bearing two 

 or more ovules on the inner face, next the base. At the time 



337 of blossoming, these pistil-leaves of the young cone diverge, 



and the pollen, so abundantly shed from the stara- 

 inate blossoms, falls directly upon the exposed 

 ovules. Afterward the scales close over each 

 other until the seeds are ripe. Then I hey sepa- 

 rate that the seeds may be shed. As the pollen 

 acts directly on the ovules, such pistil (or organ 

 acting as pistil) lias no stigma. 



315. In the Yew, and in Torreya and Gingko, 

 the gyncecium is reduced to extremest simplicity, 

 that is, to a naked ovule, without any visible 

 carpel. 



316. In Cycas the large naked ovules are borne 

 on the margins or lobes of an obvious open leaf. 

 plants have other peculiarities, also distinguishing 

 Angiospermous plants. 



All Gymnospermots 

 them, as a (lass, from 



Fig. 337. A pistil, that is, a scale of the cone, of a Larch, at the tunc of Dower- 

 ing; inside view, showing its pair <>f naked ovules. 



Pig. 33S. Branchlet of the American Arbor-Vita, considerably larger than in 

 nature, terminated by its pistillate Rowers, each consisting "f :i single scale (an 

 open pistil), together forming a small cone. 



Pro. 339. One of the scales or carpels <>f the last, removed and more enlarged, 



the inside exposed to view, showing ;i pair of ovules ou its base* 



