134 HYBRIDISING AND CROSS-BREEDING. 



the elongation of the tubes. If such views have any founda- 

 tion in truth, it is possible that, in addition to mere water, a 

 supply of the chemical ingredients which are the food of 

 plants to the style may facilitate difficult impregnations. It 

 is certainly desirable, where dry pollen is to be tried, to 

 moisten the stigma to which it is about to be applied. 



" I therefore recur to my first objection, that it is utterly 

 impossible that such a minute body (the pollen-grain) should 

 emit such a pipe and its contents that is, emit it of its own 

 substance ; and I apprehend the fact to be, that by contact 

 with the juices of the cognate plant it acquires that which 

 enables it to gain bulk for such an elongation. I conceive 

 that the abstraction of something, perhaps carbon, from the 

 juice of the stigma, is necessary to that 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 fertilise, but that which has been once 

 damp cannot do so, because it has been carbonised and has 

 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 the plant 

 necessary to carry the duct to its distant point of reception, 

 and enable it to make good its entrance when it arrives there. 

 It has, I believe, not been duly considered, that the fecunda- 

 tion 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 

 internal part or kernel, and the quickening of the embryo." 



Notable Modes in which Artificial Fecundation is possible. 

 M. Lecoq mentions the following modes in which artificial 

 fecundation may be conducted; and a series of carefully- 

 recorded experiments carried out on different individuals of 

 the same pure species, as follows, would be very valuable from 

 all points of view : 



First Degree. The flower is fecundated with its own pollen 

 that is, pollen from the same flower in which the stigma is 

 to be fertilised. 



Second Degree. The flower is fertilised with the pollen from 

 another flower on the same spike or inflorescence. 



Third Degree. The flower is fertilised like the last, but the 

 pollen is taken from a flower on another spike or panicle on 

 the same plant. 



