1 9 1 2] JONES— DI AN TH ERA 1 7 



fifth stage may have a better developed endodermis in its basal 

 internode than can be found in an ordinary seedling of the eighth 

 or ninth stage. 



One of the most striking abnormalities, however, is the failure 

 of an entire bundle to differentiate. This is frequently the case 



with 



may 



the next, may or may 



A couple of examples may be given. Counting the internodes back 



finds any trace of medullary 



the 



cal meristem, being 

 The central bundle 



/elops in the third internode, and it may 

 nodes below this. An abnormal seedlinj 



stage shows the bundle developed only in the seventh internode 

 from the top, being entirely absent elsewhere. An abnormal 

 seventeenth-stage seedling (near the end of the first growing 



bundle 



and fifteenth internodes 



Abnormalities in the peripheral bundles are less common. 

 The failure of a side bundle to fork at the bottom of the internode 

 has already been mentioned. In a single case of a mature seedling, 

 another type of abnormality was found. In one of the basal 

 internodes, the forks of one of the side bundles, undoubtedly normal 

 m its younger state, had grown together at the base, owing to the 



amount 



the 



internode 



between them 



base, the endodermis 



the endodermis 



forms a com 



the fused bundle 



trace to be inserted between its halves. 



In the basal internodes of the branches, there are usually 

 peripheral bundles. Rarelv. however, one of the side bundles 



be differentiated 



mature 



At the close of the growing season, the rhizomes produced at the 

 base of the seedlings have developed the mature type of structure 



thei 



Growth 



