STRUCTURE OF SEED. 185 



The umbilical cord bears the seed at its extremity; 

 the trace which it leaves upon it after it is detached, or, 

 in other terms, the place by which it adhered to the 

 funiculus, is its Cicatricule (cicatricula), also called 

 Hilum or Umbilicus : this place is always considered 

 as the base of the seed ; the apex is not determined 

 anatomically, as in the fruit, where the trace of the style 

 clearly indicates it; whilst the seed does not give origin 

 to any other organ, but it is found convenient to call the 

 ideal Axis of the seed, the straight or curved line, which, 

 arising from the base, proceeds at an equal distance from 

 the margins ; and we name the Apex the extremity of 

 this line. It evidently follows from these definitions — 

 1st, that the base of a seed is nearest the pedicel of the 

 fruit in erect seeds, nearest the axis or walls of the fruit 

 in horizontal ones, and nearest the style in pendent 

 ones ; 2d, that the position of the seed is only con- 

 sidered with regard to the pericarp, and not to the rest 

 of the plant ; thus, when a fruit is pendent, we say that 

 the seed is erect, when its apex is directed towards the 

 earth ; and that it is pendent if its apex point towards 

 the sky. 



The abortion of the ovules or seeds, either before 

 fecundation, during flowering or at maturity, is a phe- 

 nomenon so frequent, that it might be said, without 

 exaggeration, that it is rare to find fruits, all the ovules 

 of which have arrived at the state of ripe seeds. It may 

 be caused by the slightest derangement, either in the 

 fecundating or nourishing apparatus of the ovules ; and 

 even when these two systems of organs are in a perfect 

 state, and when no external accident deranges them, 

 there are still two frequent causes which produce these 

 abortions : — 



1st. The more or less lateral position of the flowers 

 with regard to the axis either of the spike, branch, or 



