1 62 SCOTCH PINE. 



so-called annual or growth-rings which can be seen in 

 the wood. 



The scales which cover the stem, though called by 

 the same name as the brown chaffy appendages to the 

 stem of the fern, are not trichomes like them, but 

 leaves. In addition to these scale leaves, which per- 

 form only slightly the function of true leaves, there 

 are the needle leaves, upon which the foliage work 

 chiefly depends. The delicate scales which enwrap 

 the bases of the needle leaves are not trichomes, but 

 leaves, as the rudimentary fibro-vascular bundle in 

 them shows. 



The different mode of arrangement of the scale 

 leaves (and consequently of the dwarf branches) upon 

 the terminal and lateral shoots is worthy of notice. 



Concerning the homology of the parts of the male 

 and female flowers, more especially the latter, there 

 has been and still is much controversy. It is gener- 

 ally admitted that each cluster of stamens constitutes a 

 single male flower. The scales which bear the pollen 

 sacs on their under sides are homologous with leaves, 

 as is shown by their position and anatomical characters 

 and occasionally in teratological changes. 14 Moreover, 

 the flower is subtended by a bract, and the floral axis 

 bears several (usually three) bractlets below the 

 stamens. 16 



As first announced by Robert Brown le the ovule in 

 the pines and their allies is naked, /. e. it is not sur- 

 rounded, as in the vast majority of flowering plants, 



14 Eichler, Blttthendiagramme, p. 59. 



15 Cf. Strasburger, Das botanische Practicum, p. 469. 



16 Appendix to Botany, Capt. King's Voyage, iv, p 103. 



