SECTION 10.] 



PISTILS. 



109 



tiguous margius of two pistil-leaves grown together. There is every grada- 

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

 even in the same genus, sometimes even in different stages in the sp.nie 

 pistil (Fig. 335, 336). 



§ 2. GYMNOSPERMOUS GYNCECIUM. 



313. The ordinary pistil lias a closed ovary, and accordingly tlie pollen 

 can act upon tlie contained ovules only indirectly, llirougli tlie stigma. 

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



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

 vessel. The counterpart term is 



Gymmspermous, meaning naked-seeded. This kind of pistil, or gyiioe- 

 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 (306), those of the 

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

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



and the pollen, so abundantly shed from the stam- 

 iuate 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) has no stigma. 



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

 the gynoeeium 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 obviims open leaf 

 plants have other peculiarities, also distinguishing 

 Angiosfermous plants. 



All Gymnospermods 

 them, as a class, from 



Fig. 337. A pistil, that i.s, a scale of the cone, of a Larch, at the time of flower- 

 ing; insitle vii'w. showing its pair of iiakeil ovules. 



Fig. 338. Branclilet of the American Arbor-Vitse, considerably larger than in 

 nature, terniinatiMl by its pistillate flowers, each consisting of a single scale (an 

 open pistil), together forming a small cone. 



Fig. 339. One of the scales or carpels of the last, removed and more enlarged, 

 the inside exposed to view, showing a pair of ovules on its base. 



