INTRODUCTION. xix 



123. The ovary being the essential part of the pistil, most of the terms relating to 

 the number, arrangement, etc., of the carpels, apply specially to their ovaries. In some 

 works each separate carpel is called a pistil, all those of a flower constituting together 

 the gyncecium ; but this term is in little use, and the word pistil is more generally 

 applied in a collective sense. When the ovaries are at all united, they are commonly 

 termed collectively a compound ovary. 



124. 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 

 very few genera, however, the ovaries are more numerous than the petals, or indefinite. 

 They are in tViat case either arranged in a single whorl, or form a head or spike in 

 the centre of the flower. 



125. The terms monogynous, digynous^ jjolygynous^ etc. (with a pistil of one, two, or 

 more parts), are vaguely used, applying sometimes to the whole pistil, sometimes to the 

 ovaries alone, or to the styles or stigmas only. Where a more precise nomenclature is 

 adopted, the flower is 



monocarpellary, when the pistil consists of a single simple carpel. 



hi-, tri-, etc., to poly-carpellary, when the pistil consists of two, three, or an inde- 

 finite number of carpels, whether separate or united. 



syncarpous, when the carpels or their ovaries are more or less united into one 

 compound ovary. 



apocarpous, when the carpels or ovaries are all free and distinct. 



126. A comjyound ovary is 



unilocular or one-celled, when there ai'e no partitions between the ovules, or when 

 these partitions do not meet in the centre so as to divide the cavity into several cells. 



plurilocular or several-celled, when completely divided into two or more cells by 

 partitions called dissepiments {septa), usually vertical and radiating from the centre or 

 axis of the ovary to its circumference. 



hi-, tri-, etc., to multi-locular, according to the number of these ceils, two, three, 

 etc., or many. 



127. In general the number of cells or of dissepiments, complete or partial, or of 

 rows of ovules, corresponds with that of the carpels, of which the pistil is composed. 

 But sometimes each carpel is divided completely or partially into two cells, or has two 

 rows of ovules, so that the number of carpels appears double what it really is. Some- 

 times again the carpels are so completely combined and reduced as to form a single cell, 

 with a single ovule, although it really consist of several carpels. But in these cases the 

 ovary is usually described as it appears, as well as such as it is theoretically supposed to be. 



128. In apocarpous pistils the styles are usually free, each bearing its 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 stylCf with several hranclies, when the styles are connected at the base, but 

 separate below the point where the stigmas or stigmatic surfaces commence. 



one simple style, loith several stigmas, when u.uited up to the point where the stig- 

 mas or stigmatic surfaces commence, and then separating. 



one simpile style, %mth a hranched, lohed, 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 style?, 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 liair-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 carefid 

 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 



