xviii OUTLINES OF 



one simple style, with several stigmas, when united tip to the point where the 

 stigmas or stigmatic surfaces commence, and then separating. 



one simple style, with a branched, lobed, toothed, notched, or entire stigma (as the 

 case may be), when the stigmas also are more or less united. In many works, how- 

 ever, this precise nomenclature is not strictly adhered to, and considerable confusion 

 is often the result. 



130. In general the number of styles, or branches of the style or stigma, is the same 

 as that of the carpels, but sometimes that number is doubled, especially in the stigmas, 

 and sometimes the stigmas are dichotomously or pinnately branched, or penicillate, 

 that is. divided into a tuft of hair-like branches. All these variations sometimes make 

 it a difficult task to determine the number of carpels forming a compound ovary, but 

 the point is of considerable importance in fixing the affinities of plants, and, by careful 

 consideration, the real as well as the apparent number has now in most cases been 

 agreed upon. 



131. The Placenta is the part of the inside of the ovary to which the ovules are 

 attached, sometimes a mere point or line on the inner surface, often more or less thick- 

 ened or raised. Placentation is therefore the indication of the part of the ovary to 

 which the ovules are attached. 



132. Placentas are 



axile, when the ovules are attached to the axis or centre, that is, in plurilocular 

 ovaries, when they are attached to the inner angle of each cell ; in unilocular simple 

 ovaries, which have almost always an excentrieal style or stigma, when the ovules are 

 attached to the side of the ovary nearest to the style ; in unilocular compound ovaries, 

 when the ovules are attached to a central protuberance, column, or axis rising up from 

 the base of the cavity. If this column does not reach the top of the cavity, the pla- 

 centa is said to he free and central. 



parietal, when the ovules are attached to the inner surface of the cavity of a one- 

 celled compound ovary. Parietal placentas are usually slightly thickened or raised 

 lines, sometimes broad surfaces nearly covering the inner surface of the cavity, some- 

 times projecting far into the cavity, and constituting partial dissepiments, or even 

 meeting in the centre, but without cohering there. In the latter case the distinction 

 between the one-celled and the several-celled ovary sometimes almost disappears. 



133. Each Ovule (121), when fully formed, usually consists of a central mass or 

 nucleus enclosed in two bag-like coats, the outer one called primine, the inner one 

 sectindine. The chalaza is the point of the ovule at which the base of the nucleus is 

 confluent with the coats. The foramen is a minute aperture in the coats over the 

 apex of the nucleus. 



134. Ovules are 



orthotropous or straight, when the chalaza coincides with the base (36) of the 

 ovule, and the foramen is at the opposite extremity, the axis of the ovule being straight. 



campylotropous or incurved, when the chalaza still coinciding with the base of 

 the ovule, the axis of the ovule is curved, bringing the foramen down more or less to- 

 wards that base. 



anatropous or inverted, when the chalaza is at the apex of the ovule, and the 

 foramen next to its base, the axis remaining straight. In this, one of the most frequent 

 forms of the ovule, the chalaza is connected with the base by a cord, called the rhaphe, 

 adhering to one side of the ovule, and becoming more or less incorporated with its 

 coats, as the ovule enlarges into a seed. 



amphitropous or half -inverted, when the ovule being as it were attached laterally, 

 the chalaza and foramen at opposite ends of its straight or curved axis are about 

 equally distant from the base or point of attachment. 



§ 12. The Receptacle and Relative Attachment of the Floral Whorls. 



135. The Receptacle or torus is the extremity of the peduncle (above the calyx), 

 upon which the corolla, stamens, and ovary are inserted. It is sometimes little more 

 than a mere point or minute hemisphere, but it is often also more or less elongated, 

 thickened, or otherwise enlarged. It must not be confounded with the receptacle of 

 inflorescence (74). 



