CRUCIFEILE 143 



The spathulate type of cotyledons seems to be largely due 

 to growth subsequent to germination, as we meet with it in a 

 few more or less widely distinct genera having differently 

 shaped seeds and fruits, and widely diverse embryos. Bunias 

 orientalis (fig. 176) may be given as an instance of this type. 

 The cotyledons are spirally coiled in the seed, with their 

 apices in the centre of the coil, where they are distinctly 

 narrowed, but after attaining their full size they are spathulate, 

 obtuse, entire or slightly emarginate, unequal in length, 

 tapering to a short, petiole-like, shortly connate base, and 

 showing a few alternate, ascending veins on each side of a 

 strong midrib. The average length of three of the longer 

 cotyledons measured was 42 mm., and of three of the shorter 

 ones 33 mm. The seed-leaves of Cakile maritima are linear- 

 spathulate, obtuse, entire, unequal, sessile, tapering to the 

 base, one-nerved, subfleshy. The inclination to assume this 

 shape no doubt originates in the seed, which is oblong, slightly 

 notched at the base, and 3-3*5 mm. in length. The upper 

 division of the two-seeded fruit is the longer and contains 

 the larger seed, which is laterally compressed. The cotyle- 

 dons are accumbent, sometimes oblique, and lying on the 

 edge of one cotyledon only, which would tend to make 

 one of them narrower than the other, but the inequality in 

 length is more difficult to account for. The cotyledons of 

 C. americana both before and after germination are propor- 

 tionally broader than those of C. maritima. The seeds of 

 the former are however longer, measuring 5-6 mm., and the 

 cotyledons after germination are spathulate, obtuse, sessile, 

 but tapering to the base, and much more unequal than those 

 of C. maritima. 



The divided cotyledons of Schizopetalon Walkeri and 

 Lepidium sativum have been already described. One 

 advantage of this form is perhaps that it enables each of the 

 four segments to emerge from the testa independently of the 

 others. The cotyledons of Schizopetalon Walkeri (fig. 160) 

 are generally divided almost to the base, although there are 

 cases where they are merely forked like those of Eschscholtzia 

 californica in the closely allied Order Papaveraceas. The coty- 

 ledons become curved and then coiled at a very early age of 



