580 GARDEN MANAGEMENT. 



§ 1.— PR0PAGATI0!T. 



1832. The Eose is propagated by seeds, by cuttings, by layers, by bud- 

 ding, and by grafting, and new varieties are produced by hybridization, — 

 that is, by transfusing the male pollen of one flower into the stigma of another, 

 with the object of producing seed which shall reproduce the best properties of 

 both the parent plants. 



1833. Hylridlzaiion. — Botanists apply this term to a plant produced from 

 two parents of different species ; and of all products of vegetation the rOiSe 

 has, perhaps, yielded the most numerous varieties to cultivation : this has 

 also occurred, in all probability, in a state of nature. A plant is in flower, 

 and the wind, an insect, or the industrious hand of the gardener, conveys the 

 pollen or powdery matter which accumulates on the ripe style of the mal& 

 flowers, to the equally ripe stigmata of the female flower. The stigma 

 absorbs the moisture from the dusty particles of the pollen, and it fructifies ; 

 the seed which results from the operation produces a new variety, partaking 

 of the more prominent properties of both parents. 



1834. In order to produce this result, however, both parents must have 

 certain qualities in common. In the case of animals, a horse breeds with an ass, 

 and produces a mule ; but it would not with a cow, nor would the amaryllis, 

 which has been the subject of very interesting experiments in hybridization, 

 succeed when crossed with the crinum or any flower of a difierent species, 

 so as to be reproductive itself. The reproductive power thus seems to be 

 the line of demarcation between species and mere variety. In fact, Nature 

 has placed limits be3'ond which the ingenuity of man is exerted in vain ; and, 

 although very brilliant intellects arise from time to time to interpret her 

 laws, perhaps to their own satisfaction, the subject of ''species" or kind, and 

 their chain of connection, will probably always remain a mystery. In the 

 case of vegetable products, however, it is very evident that a certain organi- 

 zation is necessary to enable one plant to cross with another ; differences, 

 perhaps, in the cellular system which are too minute for discovery even by 

 the microscope, may still be, and apparently are, sufficient for hybridiza- 

 tion once, but insufficient for reproduction ; and that limit has generally 

 served to distinguish varieties from species. 



1835. In discussing this question, M. Boitard gives many instances within 

 his own knowledge where hybridization was claimed for roses, where the 

 facts were doubtful ; and this leads him to think that roses, like many 

 other plants, have a tendency, after a time, to return to their original type. 

 ** Why not admit, then," he says, "that roses possess this tendency; is it 

 more difficult to explain, physiologically, how the wild rose comes by culture 

 to possess the odorous properties of centi folia, than to explain how a wild 

 pear, with long spines and small sour fruit, has come to be a Duchesse 

 d'Angouleme, or any other of the fine fruits of the present day?" And he 

 concludes by claiming for the rose that it consists of three species only ; 



