382 BRITISH FLOWERINO PLANTS chap. 



winged and dispersed by wind. The berries of the 

 Juniper are globular and of a dark purple blue ; the 

 seeds of the Yew are imbedded in a pulpy cup of a 

 brilliant scarlet. Both are, no doubt, carried by birds. 



The young cone makes its appearance, and the 

 pollen is shed in the spring. The pollen is long-lived, 

 and the development of the seed very slow. The pollen 

 of Pinus remains dormant, or rather completing its 

 development, for more than a year, and the ovule is not 

 fertilised till the following July, more than twenty 

 months after its commencement. The same occurs also 

 in the Juniper. Two embryos start from each fertilised 

 egg, so that several may be developed together in the 

 early stages. Only one, however, comes ultimately to 

 maturity. The cones open in dry weather, often at con- 

 siderable intervals, so that the seeds are dispersed by 

 the wind in various directions. A cone placed in a glass 

 of water will soon become tightly closed. 



The leaves are round (Pinus monophylla), semi- 

 circular, or triangular. Some are much longer than 

 others. Why is this ? I puzzled over it for some 

 time. The governing consideration is, I believe, to 

 secure a suitable amount of leaf surface. They are 

 all evergreen, but in some cases the leaves of one 

 year fall soon after those of the next are developed. 

 In others they are longer lived. In the Scotch Pine 

 they last three or even four years ; in the Norway Fir 

 eight or ten ; in the Pinsapo even as many as sixteen 

 to eighteen. Now, speaking roughly, and having regard 

 also to thestoutness of the terminal shoots, it will be found 

 that the shorter leaves have longer lives, and vice versa. 

 The longest-lived leaves amongst the Coniferse which I 

 know are those of Ahies Pinsapo, which last some eigh- 

 teen or twenty years. Those of Welwitschia, a member 

 of the order Gnetacese, however, are said to reach even 

 a century. This remarkable genus ^ is represented by a 

 single species inhabiting the desert country in south- 

 west tropical Africa. It has a short thick stem like a 



^ Described by Sir J. Hooker in Trails. Linn. Soc. xxiv. (1863). 



