OBSERVATIONS UPON MULING AMONG PLANTS. 13 



cuttings, layers, &c., is obviously of great consequence to agri" 

 culturists. 



Little lias been done at present in the hybridizing of cereals, 

 but Mr, Herbert believes that more useful varieties tlian at pre» 

 sent exist of wheat, oats, and barlay might be produced by 

 combining the fruitfulness of one variety with the hardiness of 

 anotlier, to both of which might be added the thin skin and con- 

 sequent superior weight of a third. Knight's wrinkled peas are 

 a proof of what may be done by hybridizing, and it is probable 

 that much might be effected in beet, cabbages, carrots, celery, 

 &c., by especial attention to this point. 



Amongst woody plants also there are instances of peculiarly 

 luxuriant growth, such as Lycium barhato-afrum. Varieties 

 therefore might be produced, of much more rapid growth, which 

 for some purposes might have their value, though tiie quality of 

 the timber would probably suffer. 



Another peculiarity of hybrids is their precocity, of which 

 advantage may be taken where early fruit is desirable^ or where 

 the summers are not long enough to ripen the later fruit. 



A very important quality of hybrids is also their power in 

 very many cases of enduring a greater degree of cold than the 

 pure species from which they are derived, and hence the accli" 

 matisation of many useful plants by means of hybrid forms or 

 varieties may be effected. The hybrids, for instance, of NicO' 

 tiana are far less susceptible of frost than their pure parents, a 

 circumstance of very great importance if the cultivation of to- 

 bacco were to be materially extended. 



The great fruitfulness of many hybrid varieties is also a ma» 

 terial point as regards tiieir useful qualities, especially in orchards 

 and vineyards, and where ornament, effect, or what the Ger- 

 mans call aesthetic botany in its various brandies is concerned, 

 hybrids supply an endless subject of experiment. 



And lastly, tlie longer duration of many hybrids and their 

 more persistent larger blossoms make them especial objects of 

 favour and delight. 



The great difficulty in the way of experiment is the frequent 

 want of fertility in the seeds of hybrids, and their tendency to 

 wear out, wherever there is a possibility of impregnation from 

 neighbouring varieties. 



An appendix is subjoined to the work, containing an account 

 of themanipulations of which tiie author made use in his expe- 

 riments, and a list extending to above forty pages of all the 

 species which have been submitted to experiment. 



