





* 







286 



DR. H. T. MASTERS ON THE MORPHOLOGY, 















with that of the lateral buds, is probably the cause of the peculiar 

 beaded or cupped growth of some Conifers, as in Abies subalpina, 

 where the ends of the shoot each year sometimes swell out iuto 

 well-marked dilatations, or even into cup-like forms, the terminal 

 growing-point being, as it were, included within, or at the base of, 

 the cup formed by the faster-growing side-buds. A remarkable 

 instance of this kind occurred in an Araucaria growing in the 

 grounds at Bodorgan, Anglesea, whereThad the opportunity of 

 seeing it. In A. Pindrow and some others the arrest in develop- 

 ment of the terminal bud is a marked feature, and one which 

 interferes with the symmetrical appearance of the tree. 

 . In the Cupressinea) the branchlets or smaller branch-systems 

 are usually flattened either front side to side, or from above 

 downwards. This appearance arises from the production of the 

 branchlets in one plane only, and from the regular conduplica- 

 tion of the lateral leaves (the median ones remaining flat and 

 appressed). In these plants a certain number of branchlets with 

 their leaves have a sort of individuality of their own, so as to 

 resemble compound leaves, the pinnae being represented by sepa- 

 rate branchlets. This individuality is still further indicated by 

 the fact that groups of branchlets, or branch-systems, fall off 

 singly as the individual leaves of deciduous plants do and by 

 a similar process called in this case " cladoptosis " *. 



Variations further occur arising from the degree of ramifica- 

 tion, as in bi-, tri-, quadri-pinnate ramification. In some cases 

 this pinnate mode of branching may take place regularly on 

 both sides of the branch or on one side only, and in that case 

 generally on the distal side, or that furthest removed from the 

 axis, often (as in Thuya) causing a curvature of the branchlet, 

 whose concavity is directed towards the main axis. A similar 



one-sided ramification is observable in many Algae, e. g. Pjo- 

 camium. 



In further illustration of these remarks examples may be cited 

 in various genera. 





























UD 





horizontal, in an ascending or in a descending plane in different 

 varieties. The leaves are in decussate pairs, lateral buds being 









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Trans. Eoy. Soc. Edinb 



Leaves of Conifers 



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