28 MORPHOLOGY OF SPECIES 



all terminate in spines. In one specimen taken at random, out 

 of fourteen well-developed branches, only one terminated in an 

 apical bud. Even when present, however, the terminal buds do 

 not often pass through the winter, beirig generally so sensitive to 

 cold that they are killed by a fairly sharp frost. Some few occa- 

 sionally are seen to survive the winter, and these continue to grow 

 during the next year. Where accessory branches are not visible 

 or apparently not devc'loped, rudimentary branches will be found 

 in the form of buds placed in the same position, between the 

 foliage leaf and the primary spine, ready to grow should an oppor- 

 tunity be given them, and protected against injury by being care- 

 fully packed between the two and surrounded by scale leaves 

 covered with hairs. 



The accessory branches have the same structure as the mam 

 axis. They bear in their turn primary spines and accessory 

 branches, and these latter again branch in the same manner. As 

 they never grow very long and generally only for one year, we get 

 the compact habit of the plant, which has been already mentioned. 



The flowers are generally borne on the primary spines, but at 

 the apex of the accessory branches they are produced directly in 

 the axils of the leaves in place of the primary spines ; and on the 

 primary spines themselves the flowers replace secondary spines. 

 They are only formed on those parts of the plant which are more 

 exposed to light than the others. This may be illustrated by 

 observations on a short branch taken at random from a furze 

 plant. In this case there were no flowers at all at the base, as 

 this part of the branch was completely surrounded by other 

 branches. J'he first flowers were produced at a distance of 12 cm. 

 from the apex on the primary spines. Starting, therefore, just 

 below this, and taking branches here and there as we pass upwards 

 to the apex, we find a regular progression in the number of flowers 

 produced, as the primary spines become more fully exposed to light : 



Branch i. — Seven leaves, all with secondary spines in their 

 axils. No flowers. 



Branch 2, — Eight leaves ; the lower six with spines, the two 

 upper ones with flowers in their axils. 



Branch 3. — Seven leaves ; first five with spines, the sixth and 

 seventh with flowers. 



