









280 DR. M. T. MASTERS ON THE MORPHOLOGY, 



that the position of the xylem is wholly exceptional, if the needle 

 is to be considered foliar *. 



Eichler (in litt.) looked upon the double needle of Sciadopitys 

 as an euation from the primary leaf and extended the same inter- 

 pretation to the seed-scale of Abietiueae, as will be mentioned 

 hereafter. 



■ 



The evidence derivable from comparative morphology, terato- 

 logy, and anatomy is summarized in an article in the i Journal of 

 Botany ' by the present writer t- The suggestion may be made 

 that the needle is a shoot, the distal or anterior portion of 

 which (in relation to the axis) is abortive, just as the leaf is 

 considered byM. Casimirde Candolle to be a branch the proximal 

 or posterior part of which is not developed J. In Sciadopitys, 

 according to this view, the cladode would consist of two branches, 

 or of two shoots, in union side by side as far as the notch, the 

 leafy dilatations on each side of the central groove would be simply 

 flattened axes, not displaced leaves, and the occasional presence of 

 a bud at the tip would be only an accidental occurrence and one 

 which in any case would not invalidate the axial nature of the 

 cladode. 



The subject must necessarily be referred to again in treating 

 of the seed-scale; but it may here be remarked that all the 

 authors, whatever view they have adopted as to its morphology, 

 consider the double-needle of Sciadopitys as the homologue of the 

 seed-scale of Abietineae. The absence of a bundle-sheath in the 

 seed-scales may, however, be cited as one point of difference. 

















Eamification. 



One of the principal peculiarities of the branches and 

 stems of Conifers arises from the presence or absence of promi- 

 nent swellings or " pulvini " (fig. 14). In the species otHcea and 

 of some of the species of Pin us the base of the leaf is, as it is 

 called, " decurrent," the cortical tissues being thickened and 

 forming peg-like projections (see p. 264). In Abies and in the 





issensch. 1883. d. 216. See also Bower in Proceeding! 



1884. 



Botany, April 1884 



Sciadopitys" in Journal of 





Thlorie de la feuille (1868). 







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