INTRODUCTION TO BOTANY. xv 
the slit or opening faces the pistil ; extrorse, when the opening is towards 
the circumference of the flower. 
101. Very peculiar structures of the anther and pollen will be described 
under the Orders Aselepiadee and Orchidee. 
§ 12. The Pistit. 
102. The Pistil or female system always occupies the centre of the 
flower and terminates the growing axis. It consists of one or more carpels, 
containing the germs of one or more seeds. The pistil is usually sessile ; 
if stalked, its stalk is called a podocarp (but this must not be confounded 
with the gynobasis*or gynophore) (127). 
103. A complete pistil consists of three parts :— 
1, the ovary or enlarged base, which includes a cavity or cell 
(Joculus), containing one or more ovules (117), which are the 
earliest condition of the future seeds. 
2, the style, a prolongation of the carpel usually proceeding from 
the summit, sometimes from the side of the ovary, and sup- 
porting 
3, the stigma. This is various in appearance, sometimes a mere 
point to the style, sometimes a flattish cushion, sometimes a 
narrow line, sometimes a broad lamina; but it always consists 
of loosely cellular substance, destitute of epidermis, and covered 
with minute protuberances, called papilie. It is through the 
stigmatic tissue that the fertilizing influence of the pollen is 
conveyed to the ovules. 
104. The sty/e is often wanting, and the stigma is then sessile, but in the 
perfect pistil there is always at least one ovule in the ovary, and some 
portion of stigmatic tissue. Without these the pistil isimperfect, and said 
2 be barren, abortive, or rudimentary according to the degree of imper- 
ection. 
105. The ovary being the essential part of a pistil, most of the terms 
relating to the number, arrangement, etc., of the carpels apply specially to 
the ovary. In general, the term ovary is used to designate all the carpels 
of a flower, especially if they are at all united. 
106. The number of carpels or ovaries in a flower is frequently reduced 
below that of the parts of the other floral whorls, even in flowers otherwise 
symmetrical. In a comparatively small number of genera the carpels are 
more numerous than the petals, or indefinite; in these cases they are 
either arranged in a single whorl, or form a head or spike in the centre of 
the flower, as in the Buttercup and Anemone. 
107. The terms monogynous, digynous, etc., polygynous (1, 2, or many 
ovaries) are vaguely used, applying sometimes to the whole pistil, some- 
times to the carpels alone, and sometimes to the styles or stigmas. When 
a more precise nomenclature is used, the flower is monocarpellary, when the 
pistil consists of a single, simple carpel; d7-, tri-, etc., or polycarpellary, 
when the pistil consists of 2, 3, or many carpels, whether separate or united. 
108. A pistil is synearpous when the carpels are united into one com- 
pound ovary; apocarpous, when the carpels are free or separate. 
109. A compound ovary is, 
unilocular, or one-celled, when there are no partitions between the 
ovules, or when the partitions.do not meet, so as to divide the 
cavity into several chambers. 
plurilocular, or several-celled, when completely divided into two or 
more cells by partitions called dissepiments (septa). These 
dissepiments are usually vertical, radiating from the centre or 
axis of the ovary to its circumference. 
