198 VEGETABLE ORGANOGRAPHY, 



not as yet been seen by anatomists in a positive manner ; 

 if it exist, it is probably destroyed before maturity. Is 

 not the filament which has been seen by Richard going 

 from the hilum to the radicle in the Cycadeee and Coni- 

 ferae, that of which I have been speaking, which in these 

 families may be more persistent than in others ? 



When the embryo has not been fecundated, or when, 

 having been so, some particular cause has arrested its 

 development, we may suppose two cases possible — either 

 the whole ovule may become abortive on account of the 

 abortion of the embryo, and then the seed is wanting in 

 the place where it ought to be found ; this is most fre- 

 quently the case ; or the integuments of the seed may 

 continue to be developed, so that the seed appears per- 

 fectly formed externally, but internally it is found 

 empty : when it has albumen, this is often formed then 

 as usual ; but the place of the embryo is vacant. Thus 

 it is not rare to find seeds of the Coffee well-formed as 

 to the spermoderm and albumen, but having the cavity 

 of the embryo empty. There are some cases in which it 

 is difficult to affirm which of these abortions has taken 

 place ; thus, for example, if we examine the fruit of 

 Ranunculus lacerus, a hybrid plant, we shall find the 

 seeds well-formed externally, but empty within; is it the 

 seed which is abortive in the carpel, or the embryo in 

 the seed ? In this particular case I believe that the seed 

 is entirely abortive, because the albumen is absent ; but 

 if it took place in a plant without albumen the question 

 would be insoluble ; this happens in Centaurea hybrida, 

 the achenia of which are empty, without our being able 

 to affirm whether the spermoderm exists or not. 



The fecundated embryo generally grows very rapidly ; 

 the water of the amnios gradually disappears, either 

 wholly, or, its fluid parts being absorbed, the solid resi- 

 due concretes into albumen. In the first case, the seed 



