THE SPRUCE FIR 265 



As regards the phloem, we find distinctive 

 peculiarities in the structure of the sieve - tubes, 

 and in the replacement of true companion- cells by 

 elements of a different origin. These characters 

 suggest to us that after all we are dealing with a 

 group fundamentally distinct from Dicotyledons. It 

 will be noticed that in the points in which Conifers 

 differ most strikingly from Dicotyledons, they differ 

 equally from Monocotyledons. We shall find later 

 on that in some peculiarities of their vegetative 

 structure the Conifers approach certain families of 

 the Floweiiess Plants, which we have yet to consider. 1 



The study of the vegetative organs of these plants, 

 however, throws comparatively little light on their 

 real systematic position. We will now proceed at 

 once to make ourselves acquainted with their 

 reproductive phenomena. 



II. STRUCTURE OF THE REPRODUCTIVE ORGANS 

 a. The Male Flowers 



The male flower of the Fir, as we have already 

 learnt, is a short lateral shoot, bearing a few bracteoles 

 on the lower, and numerous spirally-arranged stamens 

 on the upper part of its axis. 



In form, the stamens are more obviously leaf- 

 like than those of Angiosperms. The pollen-sacs 

 are only two in number on each stamen, and are 

 inserted side by side on its under surface. In some 

 other Conifers, however, they are much more 

 numerous. While in Angiosperms the number of 



1 See Tart II. (Flowerless Plants). 



