292 PLANT LIFE. 



tracheids, and thus preserve a living connection with 

 the water current. The cortex cells are therefore well 

 supplied with water. The homogeneous character of 

 coniferous timber makes it very easily worked, and the 

 resin acts as a preservative against bacteria, and other 

 agents of decay ; so that this sort of wood is much 

 more used for general purposes than the wood of the 

 deciduous trees. 



The flowers of the Pine differ altogether from those 

 of the Dicotyledons. They are either male or female 

 and are generally dependent on wind-pollination. The 

 male flowers occur in little clusters. Each is a spiral 

 of stamens, and corresponds to a short branchlet or 

 needle-bearing tubercle. The stamens are placed in a 

 spiral above each other, and, when in bud, are pro- 

 tected by their tips or ends, which fit closely 

 together. The two pollen sacks are on the under 

 surface. The wind carries off the pollen, which falls 

 on to the back or into the hollowed tip of the stamen 

 below. The pollen grains are well suited for wind 

 transport. Each has the outer coat expanded into 

 two small floats which act like balloons, so that the 

 pollen is very light, and may be carried a great 

 distance. Pollen is produced in great quantity, as 

 is generally the case with wind-pollinated flowers. 



The Pine cone is very different from the male 

 flowers. It probably corresponds to a whole year's 

 shoot, and may be a contracted inflorescence, or it may 

 possibly correspond to a single flower. In most cases 

 the cones of the first year are slightly coloured. Those 

 of the Larch are particularly beautiful, and it is by 

 no means certain that they are not visited by insects. 

 Generally, these first year cones are very small (from 

 a quarter to half-an inch in length), and they are 



