212 CONTRIBUTIONS TO THE HISTORY OF CERTAIN CONtFERS. 



otlong, the midrib prominent on both surfaces, especially below ; 

 tbe epidermal cells are papilliform, and project like those of the 

 petals of a flower. There is no hypoderm ; but beneath the 

 upper epidermis are two rows of cuboidal cells, or imperfect 

 - palissade-cells full of chlorophyll. The centre of the leaf is occu- 

 pied by transfusion-tissue, and the single central fibro-vascular 

 bundle is surrounded by a ring of very large colourless cells 

 constituting the bundle-sheath. The resin-canals are three in 

 number — one on the upper surface under the projecting midrib, 

 a most unusual position, and two others on the under surface of 

 the leaf, one on each side above the epidermis, and near to the 

 edge. All three are surrounded by strengthening-cells. 



DESCRIPTION OF THE PLATES. 



Plate IL 



Abies a'mabiliSy Forbes. Sterile branch, nat. size. 



Plate III. 



Abies grandis, LindL British-grown cones, nat. size. 



Plate IV. 

 Abies nobilis, Lindl. British-grown cone, nat. size, kindly lent by Messrs, 



Veitch. A. Plan of section of leaf, showing grooved upper surface ; 

 A a. Eesin-canals. B. Seeds, scales, and bracts of cultivated specimen. 



Plate V. 

 Abies nobilis, var. magnifica, hort. Cones of home-grown specimen. 



Plate VI. 

 Abies religiosa^ Schlecht. Cone and foliage, a. Bract, two views, b. Scale. 



c. Leaf and cross section. 



Plate VII. 



Cephalotaxiis 2)€dunculafa, var. s^hceralis. Fruit and foliage. A. Longitudina 



section of fruit. 



Plate VIII. 

 Picea Omorika, Pancic. Cones and foliage. 



Plate IX. 

 Pseudolarix Kiemjyferi, Gord. Cones and foliage, nat. size, A. Leaf and cross 



section. B. Scale and bract, 



Plate X. 

 Pseudolarix Kwmpfcrl^ Gord. Branch with fruit. A. Male catkins, b, c, b, e. 



Sectional outline of stamens, f & g. Pollen. 



