380 



MORPHOLOGY. 



former line of demarcation cannot be defined in the homogeneous tissue, 

 While the lower part is thus gradually developed into the gerinen and a 

 short style, while the spermophore and seed-buds are perfected, a peculiar 

 change takes place in the upper part ; the originally open canal grows up 

 completely without leaving a trace in the interior.* The whole body 

 acquires the specific form, which in the Apocynacece is usually a short 

 cylinder, running up into a cone above ; in the Asclepiadacece commonly 

 a short pentagonal prism, also ending in a cone at the top. 



1. In the Apocy nacece (fig. 219) there is produced, on or somewhat be- 

 yond the lower or upper edge of the cylinder, a membranous, longer ( Vincd) 

 or shorter (Apocynum, fig. 219.) projecting, often wavingly- toothed (Cer- 



219 



hero) border ; above this border, or in the indentations of it, or on peculiar 

 tufts of hair, according to specific differences, begins then the secretion 

 of viscine, through which the tufts of hair and projections on the filaments 

 and the bases of the anthers become firmly glued to the stigmatic body. 

 Over the whole body a distinct epidermis has been gradually perfected, 

 excepting close beneath the border (or in Vinca just above it?). Here, 

 on the other hand, begins the secretion of the stigmatic fluid (g), and 

 this is produced in curved streaks through the whole thickness of the 

 stigmatic body (#, A), as far as the cavity of the style, and so forms a con- 

 ducting cellular tissue, which breaks through the original carpel (?) and 

 thus reaches the cavity of the germen. 



2. In the Asclepiadacece (fig. 220.) a pretty thick epidermis is likewise 

 formed over the entire stigmatic body. At its five angles it assumes a 



* Two point-like excavations are frequently seen on the upper surface, traces of the 

 confluent canal, e. g. in the Stapelice. 



819 Apocynum androsecmifolium, A, Stamen, seen on the inside : a, filament ; b, cell of 

 anther ; c c c, connective, elongated into a point above, expanded into a kind of mantle 

 at the sides and below ; d, tuft of hairs, between which the viscine is secreted by which 

 the stamen becomes glued to the stigmatic body. B, A longitudinal section through 

 the stigmatic body and a stamen : a, filament ; b, anther ; c, connective ; d, tuft of hair 

 adhering to the stigmatic body ; e, glandular corpuscle, which lies on the distinct epi- 

 dermis (z) of the stigmatic body ; /, vascular bundle, on the outer side of which ran 

 the original (now obliterated) canal of the style ; </, h, conducting cellular tissue, which 

 has been formed from the original canal of the style (from h downward), out through 

 the thickness of the carpel (from h upward), and at g constitutes a stigmatic surface. 



