THE GYMNCEOIUM, 155 



The Stigma. — ^This is a glandular body, placed on the sum- 

 mit of the style, when there is one, or immediately on the 

 ovary when there is no style. It is denuded of cuticle, and 

 secretes a viscid fluid which detains the pollen grains, and 

 causes them to emit tubes. This secretion becomes more 

 abundant as the period of fecundation approaches. 



The stigma is simple when it is connected with a single 

 pistil ; but in the compound pistil there are necessarily as many 

 stigmas as there are carpels united together. When the 

 ovaries and styles of all the carpels of a compound pistil are 

 in a state of complete cohesion and consolidation, the stigma 

 always presents a number of lobes or divisions more or less 

 deep, which clearly indicate the number of pistils which have 

 cohered together. 



The lobes of the compound stigma are excessively variable ; 

 they may be flat and pointed, and hemispherical and blunt, 

 smooth, or covered with salient papillae, or with hairs simple 

 and glandular, or with branched and plumose hairs, as in the 

 grasses. 



The Ovule is the body which is contained in the cavity of 

 the ovary and attached to the placenta, and which, after im- 

 pregnation, is transformed into the seed. It experiences in 

 this transformation remarkable changes in its structure, form 

 and position. 



In order accurately to trace the development of an ovule, 

 we must commence our observations as soon as the plant 

 begins to form flower-buds. We shall then see in the interior 

 of the ovary, forming on the placenta, a minute excrescence or 

 tubercle, formed solely of cellular tissue. This gradually en- 

 larges into a more or less obtuse conical form, constituting 

 what has been called the nucleus of the ovule. As growth 



