115 



the hypocotyl, the axis continues its growth in a curve, so that, 

 when the whole of the hypocotyl is exposed, it lies in the arc of 

 a circle, approximately (Fig. i , h ; 

 Fig. 2, a). The process of curving 

 does not always cease even after the 

 fruit falls from the tree, but continues 

 as the seedlings lie upon the ground 

 until, in many cases, the hypocotyl 

 makes a complete loop. These curv- 

 atures are frequently fixed by growth 

 so that in older seedlings the irregu- 

 larities are still to be seen. The ab- 

 sence of geotropic response may be 

 only apparent, inasmuch as growth is 



very slow, and the tissues of the ex- 



j • j i i during early stage of germina 



posed axis are rendered cumbersome . & , / , . & . 



tion ; b, dorsal view, and c 



by the load of food longitudinal section, of same ; e 



materials. embryo, end, endosperm ; int 



The hvnnrnhrl A inL 2 ' inner and outer inte § U 



Fig. 



2. a, lateral view of fruit 



hypocotyl 



ments ; h, hypocotyl ; r, radicle. 



Fig. 3. A seedling, 

 and the lower end of 

 another showing two 

 lateral roots. 



is, when developed, 

 of that club shape (Fig. 3) characteristic of 

 certain other viviparous plants, as the man- 

 groves. It is very rich in food materials, 

 especially starch, derived not alone from the 

 endosperm but as a result of its own activity 

 in starch-making. This is evident from the 

 greater weight of the hypocotyl and from its 

 green color. Stomata are present, also, in 

 numbers upon the hypocotyl. 



Under the cultural conditions in which the 

 plant under discussion was growing, the radi- 

 cle, which forms but a mere tip of the axis, 

 was frequently found in a withered condition. 

 The primary root of the embryo is, in fact, 

 often destroyed. For this reason, when the 

 embryos, usually together with the other 

 seed-parts, finally become detached from the 



