October 30, 1873. ] 



JOUKNAL OF HOKTICULTUEE AND COTTAGE GAEDEN'EK. 



the caterpillars of P. Phlscas is rapid, three weeks sufficing to 

 bring them from the egg to maturity ; but the " Coppers " now 

 about prove to be the parents of a later brood of caterpillars 

 which hybernate. They probably pass the ungenial months 

 low down, resting on the stems of grasses or upon the earth. 

 —J. K. S. C. 



ADVENTITIOUS ROOTS. 

 A CORKESPOXDEXT, (" PoxTypooL," ) is quite incorrect in noting 

 the Grape Vine as " the only cultivated plant that emits roots 



the stems need to extend further, and that these adventitious 

 roots are ready to perform good service to sustain that ex- 

 tension. 



The instances we haT« particularised are not all, and by the 

 courtesy of Messrs. Cassell ct Co. we are enabled to illustrate 

 one other. In M. Figuiei's " Vegetable ^YorI J," which they 

 have published, occurs the following passage and engraving ; — 



" In the tropical forests of America and Asia the Vanilla, 

 whose fruit is so sought after for its sweet aroma, twines its 

 slender stem round the neighbouring trees, forming an elegant. 



C'onsoi-valory ot tbe Jardm dos Plantcs, v. i 



from its stems." On the contrary, there are many plants 

 which produce roots in the same way. We have stood under 

 the Banian tree in the Botanic Garden of Calcutta, every 

 Ijranch of which had emitted an adventitious root, and every 

 one of which roots had reached, penetrated, and derived 

 nonriihment from the soil. The coimnon bane of cultivators, 

 the Conch Grass (Agropyrum repens), emits adventitious 

 roots from each joint of its creeping stems. Even the true 

 roots of the Primrose will die, yet the plant continues to 

 flourish, because adventitious roots are emitted from the stem. 

 Why the Grape Vino emits such roots from its stems is still 

 a question unanswered conclusively. They always indicate 

 vigorons growth, therefore the true roots need no such aid. | 

 It may bo, as in the case of the Banian, an intimation that i 



[[i . ■_ _i i i.itious vo'ji:^ ot tUe Va'iil^ii. 



flexible, and ai?rial garland, at once a grateful and 'pleasing 

 ornament in these vast solitudes. The underground roots of 

 the Vanilla would not be sufficient for the nutriment of the 

 plant, and the rising of the nourishing sap would take place 

 too flowly. But nature has provided for this inconvenience by 

 the adventitious roots which the plant throws out at intervals 

 along its stem. Living iu the warm and humid atmosphere 

 of tropical forests, the stronger shoots soon reach the ground, 

 and root themselves iu the soil. Others float freely in the 

 atmosphere, inhaling the humidity and conveying it to the 

 parent stem. All these processes may be observed iu full 

 operation in many well-ordered conservatories." 



We might add inany other illustrations, but it will suffice to 

 observe that the fibres which are emitted by the stems of the 



