372 SIR J. LUBBOCK PniTOBrOLOGlCAL OBSERYATIOXS. 



at both ends, and entire. The otlicr is shorter and broader, 

 2 centim. long by 1| broad, subeordate, with a large terminal 

 lobe, and one, more or less pronounced, on each side. At first 

 I thought this curious want of symmetry must be accidental. 

 It is, however, normal, and is explained by the peculiar form of 



and arrangement of the embryo (figs. 82-81) in tlie seed. The 

 fruit is an achene of peculiar form 5 it is oblong linear, sub- 

 cuneate, and laterally compressed, bifid at the apex, and crowned 

 with 2-6 unequal, closely reflexed, acute bristles, more or less 

 hairy, one-celled, one-seeded, and indehiscent. The seed is oblong 

 linear, and tapers somewhat, conforming to the interior of the 

 fruit. The embryo is large ; the longer cotyledon is doubled on 

 itself; the broader one is also turned over at the end, and wraps 

 round the narrower one*, not reaching, however, to the narrow 



r 



end of the seed: the terminal lobe of the shorter and broader 

 cotyledon is the part which is folded over, and the lateral lobes, 

 which are much smaller in the embryo, are also due to the fold, 

 as shown in figs. 82-81, 



1 



Uiisyrnvictrical Coiijledons. 



In other cases, as in the Geraniums (fig. 25), Scliinns (fig. 28)(the 

 false Pepper), Cl{toria (fig. 27), Laburnum (fig. 20), Lupines, &c., 

 there is inequality, not between the two cotyledons, but between 

 the two halves of each cotyledon. In the Geraniums this is due 

 to the manner in which the cotyledons are folded. In Cj^bbage 

 and Mustard we have seen that one cotyledon is folded inside the 

 other ; in the Geranium they are convolute (fig. 85), one half or 



Fig. 85. 



Section through enibrjo of Gcramvm, showing the mode of folding 



of the cotyledons. 



each being folded inside one half of the other— the two inner 

 halves being the smaller, the two outer the larger ones. 



In the Laburnum (fig. 26) and in Clitoria (fig. 27), where 



* The narrow cotyledon is sometimee absent. 



