(IEMMATION. 19 



as the growth of the primary branches and their principal ramifications 

 proceed just as the individual leaves of deciduous trees and shrubs do 

 and by a similar process. 



GEMMATION (BUDS). 



LEAF buds may be regarded as young undeveloped branches. When 

 leaves arise from the formative tissues rapidly one after the other 

 as in the Conifene and most Taxads, they envelop the end of the 

 shoot, in the centre of which lies the growing point. In the 

 autumn the growth is temporarily arrested, and " this arrest is 

 frequently accompanied by a corresponding check in the development 

 of the leaves which assume the form of perulce or bud scales, the 

 perulse being dilatations of the petiolar part of the leaf. In the 

 unexpanded bud the peruhv are free at the base, but as the shoot 

 lengthens they are sometimes cast off, sometimes remain attached to 

 it, in which latter case they are uplifted with the growing shoot."* 

 When the rudimentary or imperfectly formed leaves at the end of 

 a shoot are so enclosed by peruke, they form what is called true 

 winter buds. In all broad-leaved (Angiospermous) trees and shrubs, 

 a bud is formed, not only at the apex of every shoot, but also in the 

 axil of almost every leaf.f But in the Conifers, or more properly 

 speaking, in those members of the family which form true winter buds, the 

 circumstances are somewhat different as will be presently pointed out. 



True winter buds are formed throughout the Fir and Pine tribe, 

 Abietinec-e, in some of the Taxodinere (Taxodium, Sequoia sempervirens, 

 Sciadopitys) and in many Taxads (Yew, Torreya, Cephalotaxus, G-inkgo). 

 But throughout the Cupressinete and Araucarineie, and in the Taxo- 

 dinect: and Taxaceae in part, the arrest of growth is not accompanied 

 by a corresponding arrest of development and the growing point is 

 not protected by peruke or scales, but by the latest formed leaves 

 in different stages of development and which in the following 

 season attain their normal form and size like the rest. Intermediate 

 stages may often be found between the peruke and the primordial 

 leaves showing the perfect homology of the two. 



The arrangement and behaviour of the buds of coniferous trees 

 have been so lucidly discussed by Dr. Masters in the oft-quoted paper 

 in the Journal of the Linnean Society J that we cannot do better than 

 reproduce his observations in an abbreviated form. 



The very marked peculiarity of the ramification of Conifers and Taxads 

 depends mainly on the alternate development and non-development of the 

 buds. A very common feature in the arrangement of the buds is the 



* Masters in Journ. Linn Soc. XXVII. 271. 



t From some of these buds the inflorescence is developed in the place of a new shoot ; 

 morphologically the one is but a modification of the other. 

 ; Vol. XXVII. pp. 226325. 



