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JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



this ; stems from buds formed on the base of aerial stems, or on stolons, 

 rhizomes or other underground stem-structures ; steins from buds formed 

 on roots. The latter form the chief topic, but the others come under 

 notice. After a short summary of previous work, the author classifies his 

 investigations into three main groups. 



1. Herbaceous plants with dormant or accidental root-buds. In this 

 class the root-buds are only slightly better than none at all ; they are very 

 rudimentary. Dormant root-buds are small protuberances on the roots, 

 which only develop if the plant is severely injured, but they can be made 

 to produce shoots by transplanting portions of detached roots ; they occur 

 in Geranium sanguineum, Viola elatior, Plantago media, Euphorbia 

 sylvatica, Alliaria officinalis, &c. Accidental root-buds cannot be 

 detected on the roots, but on mutilating the plant they develop and 

 produce shoots ; e.g. Bryonia dioica, Lychnis dioica, Bubus ccesius, Sec. 

 "While the leafy shoots produced from root-buds of this group are in many 

 respects like ordinary shoots, they differ in growth and internal structure, 

 in the size, shape, and texture of the leaves, and in not bearing flowers. 

 Their structure altogether is less developed than the normal, and in 

 consequence the majority of them do not survive the winter. 



2. Trees and shrubs with radical shoots. Under this class are included 

 the radical shoots of trees whether their origin be root-buds (e.g. Poplars, 

 English Elm, Robinia, &c), or dormant buds or suckers (e.g. pedunculate 

 Oak), or from stools (Oak and Black Poplar). Radical shoots are dis- 

 tinguished by exuberant growth, long internodes, and large leaves. The 

 tendency, in short, is towards a more herbaceous mode of growth, and the 

 more woody the normal stems of the species examined, the greater the 

 difference, externally and internally, between ordinary branches and radical 

 shoots. The Poplars (black, white, and aspen) are described in consider- 

 able detail, while many common trees are considered briefly. 



3. Herbaceous plants with root-buds which normally produce shoots. 

 All the plants of this group have rcot-buds, which in the natural course of 

 growth produce flowering shoots. In Toadflax (Linaria vulgaris) the 

 stem produced directly from the seed is sterile and soon dies ; the later 

 growth proceeds from radical buds, which alone produce flowering shoots. 

 In external features and internal structure these radical shoots are more 

 differentiated than the primary stem. The same holds good for Euphorbia 

 Cyparissias, Convolvulus arvensis, and Carduus arvensis. In Sonchus 

 arvensis the primary stem is fertile, also the stems from radical buds ; in 

 structure the primary and radical shoots are almost equal. In Campanula 

 rottmdifoUa there are three kinds of stem — from the seed, from rhizomes, 

 and from root-buds. Hypericum perforatum is similar except that it has 

 shoots produced from suckers instead of rhizomes. In these cases the 

 radical stems are intermediate between the primary, which is better 

 developed, and the rhizome or sucker shoots, which are poorer. 



The paper is provided with sectional summaries. The figures show 

 variations in the leaves from different kinds of shoots, and the plates are 

 excellent drawings of morphology and structure. — W. G. S. 



Root-pruning-. By J. & U. (Journ. Ilort. September 24, 1903, 

 p. 279).— This is often neglected in orchards if the annual growth pre- 



