





ANATOMY, AND LIFE-HISTOBr OP THE CONTFEBJG. 



281 





Strobus 



form 























rhythmic alternation 

 in relatively definite 



X-2 



Fig. 14.— Pulvini of 

 stem of Picea. 



The mode of branching in the Qpnifers is often 

 so distinct in appearance as to give rise to the 

 impression that there must be some essential 

 difference between the ramification of these and 

 that of other plants. This, however, is by no 

 means the case. 



It is always monopodial, never sympodial 

 or dichotomous. The variations depend pri- 

 marily upon the development of the buds in 

 particular situations and upon their non-deve- 

 lopment in others. Development and non- 

 development occur in 

 as regards time, and 



positions as regards space*. The unusual 

 degree of regularity with which these phenomena do or do 

 not occur brings about a style of ramification characteristic 

 indeed, but still not essentially different in kind from that which 

 occurs in many other plants. 



In many Conifers the relatively large development of the trunk 

 as compared with that of the branches, the apparently verticillate 

 arrangement of the latter, their spreading direction, and their 

 gradual diminution in length from below upwards, give rise to a 

 tree of markedly pyramidal form. The virtually verticillate ar- 

 rangement of the primary branches is associated with a bilateral 

 disposition of the branches of lower order and with a like arrange- 

 ment of the leaves. 



In other cases, where the disproportion between the stem and 

 the main branches is not so great, we have, as in many Pines, 

 Tews, &c, the bush form, and this becomes modified into the 



ne-shaped form, as in various Thuyas and Cypresses, the 



fll 



decurrens 



the globose form, as in varieties of Thuya orientalis, &c. Fas- 

 tigiate forms like the Irish Tew owe their appearance to the 

 general upward direction of their branches. This upward direc- 

 tion is due to the retention in adult life of the juvenile mode of 

 growth. Correlative changes are observable in the arrangement 

 of the leaves, which do not in these cases become twisted at the 



See Sachs's Text-book, ed. Vines (1882), p. 239; Goebel, Outlines, ed. 

 Garasey and Balfour (1887), p. 320. 





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