ON HYBRIDIZATION AMONGST VEGETABLES. 



9 



increase of bulk, and in some cases that atmospherical moisture is 

 essential to it. Hence it arises that old pollen which has been kept 

 perfectly dry may act so as to fertilize, but that which lias been 

 once damp cannot do so, because it has been carbonized and lias 

 discharged its office, and is incapable of acting a second time. 

 But the probability is, that, although mere moisture may have a 

 certain effect on the pollen, there is some more chemical union 

 between the grain of pollen and the juice of t he plant necessary 

 to carry the duct to its distant point of reception, and enable it 

 to cry " Open Sesame," and make good its entrance when it 

 arrives there. It has, I believe, not been duly considered, that 

 the fecundation of the ovules is not a simple, but a complicated 

 process. There seem to me to be three or four several processes 

 — the quickening of the capsule of the fruit, the quickening of 

 the outer coats of the seed itself, and the quickening of the in- 

 ternal part or kernel, and the quickening of the embryo. 



Whoever tries to raise mule Alstroemerias from A. aurea by 

 some cognate species, will find, under favourable circumstances, 

 every flower produce a full-sized perfect capsule, though he may 

 fail in obtaining the least enlargement of the ovules. A mule 

 raised by Mr. Bid will between Fassiflora coerulea and onychina 

 flowered this summer in my conservatory, and produced of itself, 

 to my surprise, two fine plump fruits, two inches long, of a bright 

 orange colour, there being no other Fassiflora in flower at the 

 time on the premises. On opening its beautiful fruit, it proved 

 to be empty as a bladder, the outer coat of the fruit only having 

 been fertilized in consequence of the weakness of the cross-bred 

 pollen. In other attempts at cross-breeding, or in plants that do 

 not make seed freely in our climate, he may find not only a per- 

 fect capsule, but seeds grown to full size, though containing a 

 perishable lymph, and no sound kernel. In others he may find 

 the seed either of an undue texture and substance ; or, if appa- 

 rently good, deficient in embryo. In some cases, as in the very 

 extraordinary one first noticed by Mr. Brown with respect to 

 Hymenocallis, the seed having no discoverable embryo when first 

 ripened, acquires one after lying for some weeks or months on the 

 earth. It follows, therefore, that a continued operation of the 

 pollen must be necessary to produce all these requisites for the 

 formation of a good seed. It has been said that, when the ovules 

 are fertilized, the outer coat or capsule begins to swell. This 

 does not appear to be true ; for the capsule often becomes per- 

 fect, though the ovules do not seem to have become fertilized at 

 all. It seems, therefore, a process independent thereof, whether 

 simultaneous, antecedent, or posterior ; so must the fertilization 

 of the seed-coats and of the albumen be, since they may grow 

 without an embryo : and some mysterious process must be con- 



