143 



r 



■V' 



r X 



/ 





hybrids are not only frequently sterile, but show a strong ten- 

 dency to develop gigantic or tuberous roots, and as almost In- 

 variably tending to increase largely by suckers. We must not, 

 however, ignore those obscure observations wherein we note an 

 influence of pollen in developing the ovarium, although incapable 

 of developing the ovule, and Darwin's statement that *'with an 

 orchid, the Bonatia spcciosa^ the development of the ovaria 

 could be effected by mechanical irritation of the stigma'' has not 

 received the attention from investigators that its importance de- 

 serves. Gaertner often insists, says Darwin, that the flowers of 

 . uttterly sterile hybrids, which do not produce any seed, gener- 

 ally yield perfect capsules or fruit, a fact which Naudin" has re- 

 peatedly observed in the Cucurbitaceae. It seems to be well as- 

 certained that certain plants can produce not only fruit, but fer- 



4 



tile seed, without havipg been subjected to the action of pollen. 

 Thus, as good authorities as Quatrefages^, says this is unquestion- 

 ably true, and Hooker" quotes facts of this character from Spallanz- 

 ani, Bernhardi, Ch. 'Naudin. Fresenius and Tenore, and Jussieu^ 

 and Darwin-* express also their belief. Treviranus% however, states 



that a perfect development of fruits, but with barren seeds will 

 take place with some plants without the process of fertilization. 

 There seems to exist in fruits a correlation between seedless- 

 ness and quality, especially when that quality is expressed by the 

 term tenderness of tissue. In fruits of a iine quality, tenderness 

 of the seed coating often seems a marked characteristic, as in 

 grapes, where the seeds of the improved varieties are distinctly 

 softer and more brittle than in those of the wild species ; as in 

 peaches and plums, where the tendency of a split stone is often 

 noticeable in fruit of varieties of high quality. It certainly should 

 not be overlooked that universal experience usually recognizes 

 lack of hardiness in trees of the most highly improved and de- 

 veloped varieties. This idea of correlation between seedlessness 

 and quality is by no means a new one. Thus Bacon^ wrote, 



1 Quatrefages, Metamorphoses of Man. 271, 



2 Hooker, Journ, of 15ot, :x. 53. 



3 Jussieu, Cours element- de Bot. 1840, 463. 



4 Darwin, \ii. and PL i, 4S4. 



5 Lend. Hort. See. Trans. 1854, 112. 

 6 Bacons Works, Bohn. Ed, i. 142. 



