ORGANS OF REPKODUCTION. 



289 



Fig. 626. 



The style is generally directly continuous with the ovary, 

 which gradually tapers upwards to it, as in Digitalis, in which 

 case it is more or less persistent, and then it sometimes forms 

 a part of the fruit ; at other times, however, there is a kind of 

 contraction or species of articulation at the point where the 

 style springs from the ovary, as in Scirpus, and then the style 

 always falls off after the process of fertilization is completed, 

 in which case it is said to be deciduous. 



While the style is to be regarded as being formed, in by far the 

 majority of cases by a prolongation of the apex of the carpellarj^ 

 leaf, it seems probable that in some eases, it is a mere process of 

 the placenta. Thus in the Babingtonia, as shown by Lindley 

 (Jig. 625), " the style is a direct extension of the placenta, and 

 does not even touch the carpels, but is protruded through a hole 

 in the vertex of the ovary." 



When the style is basilar or lateral, and 

 the ovary to which it is attached more or 

 less imbedded in the receptacle or thalamus, 

 it frequently appears to spring from the 

 latter part; such an arrangement is called 

 a gynohase, and the ovary is said to be gyno- 

 basic. In the Labiatse {fig- 594), and Bora- 

 gineae {fig. 595), the four ovai'ies are free, 

 but the styles become connected and form a 

 central column, which appears therefore to 

 be a prolongation of the thalamus. 



Such an arrangement must not be con- 

 founded with that of the ovaries and styles 

 of the Geranium {fig. 626). and some other 

 plants, where the axis is prolonged in the 

 form of a beak-like process, to which the 

 ovaries and styles become united, and from 

 which they separate when the fruit is ripe. 

 This prolongation of the receptacle or tha- 

 lamus is termed a carpophore, or by some 

 botanists a gyjiophore, but the latter term 

 is properly applied, as already noticed, to p^g^ 

 the stalk which occasionally supports the 

 ovary, as in the Passion-flower, Dianthus, 

 &c. (See page 281.) 



We have already stated that when the styles of a syncarpous 

 pistil are distinct, that they usually correspond to the number of 

 carpels of which that pistil is composed. It sometimes happens, 

 however, that the style of each carpel bifurcates or becomes 

 forked, as in some Euphorbiaceae, either once {figs.^\2 and 628), 

 or twice {fig. 627); so that the number of the styles above, is 

 then double or quadruple that of the carpels. When two or 

 more styles are united into one body, this is termed a compound 



The carpophore 

 c, of a Geranium, with 

 the rolled back carpels, 

 car. 



