158 BOTANY. 



Fig. P : Germen cut to show the ovules. 



Fig. R : Round pollen, the external membrane of which 

 bursts, and the interval forms a species of tube which bursts in 

 its turn and suffers the pollenic granules to escape. 



Fig. T : Section of a stigma, to show how it is traversed by 

 the grains of the pollen. 



Fig. X: 1, stigma; 2, conducting tissue; 3, expansion of 

 the conducting tissue to receive the ovule; 4, epicarp; 5, 

 endocarp ; 6, nutritive vessels of the ovule ; 7, raphe ; 8, 

 chalaza; 9, primine; 10, secundine; 11, exostome and en- 

 dostome ; 12, tercine ; 13, embryo. 



ACCESSORY ORGANS. 



STIPULES. 



Appendages of the leaves situated on the base of the petiole 

 and presenting the appearance of small leaves or scales. 

 [Plate 43, Fig. M.] 



TENDRILS. 



Simple threads or branches which roll themselves spirally 

 around foreign bodies to sustain the stems which are provided 

 with them. [Same Fig.] 



THORNS 



Are abortive branches and differ from prickles in being a 

 continuation of the ligneous fibre. [Plate 43, Fig. N.] 



PRICKLES. 



Appendages of the stem or branches, simply articulated 

 with the ligneous fibres. [Plate 43, Fig. O.] 



INFLORESCENCE. 



We give this name to the general disposition or arrange- 

 ment assumed by the flowers upon the stems or other organs 



