EXPLANATION OF PLATE 7. 

 Sitka Spruce [Picea sitdiensls). 



Fig. a, twig with staminate catkins. Fig. b, pistillate catkins. Fig. c, cones 

 approaching maturity. Fig. d, mature cone. Fig. e, inner view of a cone scale 

 showing the position of the two winged seeds. Fig. /, seeds. With the excep- 

 tion of tig. (', which is enlarged one and one-third times, the figures are reproduced 

 eight-ninths their natural size. 



