ORGANS OF REPRODUCTION. 



349 



in the Almond {fig. 746), Pea {fig. 160), and Bean already 

 referred to; but they frequently depart widely from such a re- 

 lation, and assume others, analogous to those already described 

 in speaking of the vernation of leaves and the aestivation of the 

 floral envelopes. Thus each of the cotyledons, may be either 

 reclinate, conduplicate, convolute, or circulate. These are the 

 commoner forms, and in such instances both cotyledons are 

 folded or rolled in the same direction, so that they appear to 

 form but one body. In rare cases they are folded in o])posite 

 directions, and become eguitant or ob volute. Other still more 

 complicated arrangements sometimes occur. 



The position of the radicle in relation to the cotyledons is 

 also liable to much variation. Thus the radicle may follow the 

 same direction as the cotyledons, or a different one. In the 

 former case, if the embryo be straight, the radicle will be more 

 or less continuous in a straight line Avith the cotyledons, as in the 

 Pansy {fig. 752, r); if on the contrary the embryo is curved, 

 the radicle will be curved also {fig. 753), and sometimes the 

 curvature is so great, that a spiral is formed, as in Bunias {fig. 

 754). In the latter case, where the direction of the cotyledons 



Fig. 752. Fig. 753. Fig. 754. Fig. 755. Fig. 756. 



Fig. 762. Vertical section of the seed of the Pansy, h. Hilum. p?. Embryo 

 ■with its radicle, r, and cotyledons, co. ch. Chalaza. al. Albumen. 



r. Raphe Fig. 753. Vertical section of the seed of a Poppy, with the 



embryo slightly curved in the axis of albumen Fig. 754. Vertical section 



of the seed of Bunim, showing its spiral embryo Fig. 7.55. Embryo 



oi ihe\\oa.dL(Isatis tiiicturia). 1. Undivided. 2. Horizontal section, c. 

 Cotyledons, r. Radicle Fig. 756. Embryo of the Wallflower. 1. Un- 

 divided. 2. Horizontal section, r. Radicle, c. Cotyledons. 



and radicle is different, the latter may form an acute, obtuse, 

 or right angle to thern, or be folded back to such an extent as 

 to lie parallel to the cotyledons : in the latter case, the radicle 

 may be either applied to their margins, as in the Wallflower 

 {fig. 756), when the cotyledons are said to be accumbent; or 

 against the back of one of them, asin Isatis {fig. 755), when 

 the cotyledons are incumbent. These terms are chiefly used in 



