208 GENERAL REVIEW. 



pared from the sap of the Birch, obtained by tapping the trunks 

 in the spring. Both Birch and Alders are easily propagated 

 by seeds sown in the autumn as soon as ripe, or in the spring 

 in shallow trenches in the open ground. Large branches or 

 truncheons of the Alder root freely when driven into the earth 

 to the depth of a foot or more, like Willows ; and propagated in 

 this way, it grows vigorously, and is valuable for strengthening 

 the banks of rapid-flowing rivers or streams. The ornamental 

 golden-leaved Alders, and the purple, weeping, cut-leaved, and 

 other cultivated forms of Birch, are readily reproduced by graft- 

 ing on their respective types as a stock. 



In a recent number of the * Illustration Horticole,' M. Andre 

 mentions having seen at a horticultural exhibition at Orleans a 

 specimen of a Purple Birch. It originated as a chance seed- 

 ling, was grafted on to the common Birch, and was thus ex- 

 hibited. It has a weeping habit, and deep violet-purple leaves. 



THE TRUMPET-FLOWER FAMILY (Bignoniacecz). 



A very beautiful group of trees or shrubs, often of twin- 

 ing or scandent habit, and represented in our gardens by 

 Bignonia, Tecoma, Catalpa, Jacaranda, Amphicoma, Eccremo- 

 carpus, and one or two other showy genera. Nearly all the 

 species are easily multiplied by cuttings, layers, or seeds, 

 careful artificial fertilisation being often necessary to obtain 

 the latter. Eccremocarpus, however, seeds very freely, and the 

 young plants often flower the first year. At Burghley, near 

 the gardener's cottage, E. scaber has naturalised itself on an 

 old stone wall, where it does not grow so luxuriantly as in 

 warm soils ; but it is far more floriferous than I have seen 

 it elsewhere, and it produces a large supply of fertile seeds. 

 The scandent species of Bignonia and Tecoma may be multi- 

 plied by simple or multiple layering ; and it would be inter- 

 esting to know to what extent the species of different genera 

 can be grafted on each other, as affording some indications 

 of their natural affinity. We already know that Bignonia 

 radicans may be grafted on Catalpa syringafolia as a stock. 

 A correspondent of the ' Horticulteur FranQais' headed back 

 some of the branches of a Catalpa, and inserted scions of the 

 Bignonia by cleft - grafting, the result being that from the 

 midst of the cool green Catalpa foliage emerged numerous 

 flowering branches of the Bignonia. It would be interesting 

 to experiment with other species of Bignonia and Eccremo- 

 carpus on the Catalpa stock, and also worked on each other. 



