Lily-kin and Rose-kin 133 



When we peel the bark off a spring bough we 

 break these forming cells, and the jelly which fills 

 them escapes, moistening the wood, and our de- 

 structive fingers also. 



During this season of vigorous growth the fibro- 

 vascular bundle of a dicotyledon consists, broadly 

 speaking, of three parts the wood, the bast, and 

 the generative tissue, full of sap and vitality, 

 which lies between them. 



By the end of summer, however, a transverse 

 section of the bundle in question will show no ac- 

 tively-dividing constructive cells. The formation 

 of new substances is over for the season, and each 

 fibro-vascular bundle now seems to consist of 

 but two important elements, wood-vessels and bast- 

 tubes. 



But the work of tissue-building in this kind of 

 a bundle is not finished. It is merely arrested. 

 The constructive life at the core is "scotched, 

 not killed," and after remaining dormant all winter 

 it reawakens in spring. Then a zone of young 

 cells instinct with creative vigor will come into 

 being between wood and bast, and tissue-building 

 ' will recommence. 



So the fibro-vascular bundles of roses and their 

 kin are capable of renewing their growth, year 



