244 TRANSACTIONS, NATURAL HISTORY SOCIETY OF GLASGOW. 



that of new roots being formed above partially 

 broken parts of the brittle stem of IinjDcUiens Noli- 

 me-tcuigere, which lengthened till they reached the 

 earth. He refers to the Banyan-tree as a striking 

 example of this tendency, and gives many instances 

 of leaves and stems sending forth roots. He also 

 treats of the variations in the shape and colour of 

 roots. 



The anomalies of the stem and branches he refers 

 to the effects of soil, climate, and cultivation, and 

 shows how these causes affect the development of 

 thorns, prickles, and hairs. Age he also gives as a 

 factor that makes some plants jagged and cantank- 

 erous, as Astragalus Tragacanthi, and some of the 

 Miinosce. 



" The tendrils of Vines," he says, " occasionally 

 produce flowers and bear fruit, from which it 

 would seem that they are only abortive branches ; 

 and in the Bladdered Fumitory (CorydaUs vesicaria) 

 the ends of the branches are terminated 

 with tendrils, which frequently change either parti- 

 ally or entirely into leaves." The importance of these 

 observations ^vill be more fully comprehended on 

 reference to Darwin's Movements and Habits of 

 Clivihing Plants and his remarks on CorydaUs 

 claviculata and Vitis vinifera. 



Hopkirk deals with grafting, natural and artificial. 

 He recognises the fact that no new varieties are 

 produced by grafting, but that it preserves and 

 propagates those already existing. He dismisses 

 the absurdities of the old writers as to grafts 

 on trees of quite different natures. "It is, 

 however," he adds in a note, "a very surprising 

 and altogether unaccountable circumstance that 

 plants which do not lose their leaves and 

 are evergreen can be grafted upon others which 

 are deciduous, provided they are nearly allied. 

 Thus, the Common Laurel (Primus Lauro-Cerasus ) 

 may be grafted upon the Perfumed Cherry Tree 

 ( Prunus Makaleh), and the Broad -leaved Medlar 



