n6 



BOTANY 



series of sporophylls is present. Those which bear 

 stamens only are known as staminate flowers ; those 

 which possess only carpels are called pistillate. Such 

 flowers are generally very small and inconspicuous. 



Another type of flower altogether is found in the 

 group of plants called Gymnosperms, which is repre- 

 sented in this country by the fir trees and their allies. 



FIG. 47. A, twig of fir tree bearing a young female cone; B, twig bearing 

 several male cones; C, ovaliferous scale from A showing two ovules 

 on the under surface. (After Scott.) 



In most of these the sporophylls are arranged in a close 

 spiral round an axis and form the structures known as 

 cones. The fir tree itself bears two kinds of these cones 

 (Fig. 47) each bearing one kind of spore. The smaller 

 cones are composed of a large number of very small 

 leaves arranged spirally round the axis of the flower, 

 covering or overlapping each other very closely. On 

 the back of each leaf or sporophyll are two sporangia, or 

 pollen sacs, each containing a large number of micro- 

 spores or pollen grains. Larger cones are developed in 

 connection with the production of the megaspores. The 



