XXXU OUTLINES OP BOTANY. 



own stigma. Very rarely the greater part of the styles, or the stigmas 

 alone, are united, whilst the ovaries remain distinct. 



129. Syncarpous flowers are said to have 



several styles, when the styles are free from the base. 



one style, with several branches, when the styles are connected at the 

 base, but separate below the point where the stigmas or stigmatic surfaces 

 commence. 



one simple style, with several stigmas, when united up 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, however, 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 deter- 

 mine 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 thickened or raised. Placentation is therefore the indi- 

 cation 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 uniloenlar simple ovaries, which have almost always an excentrical 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 placenta 

 is said to be 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, sometimes 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 secundine. The chalaza is the point of the ovule at which 

 the base of the nucleus is confluent with the coats. The foramen is a mi- 

 nute aperture in the coats over the apex of the nucleus. 



1 34. 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 xia 

 of the ovule being straight. 



campylotropous or incurved, when the chalaza still coinciding with the 



