l62 



MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 



from the base and by the basal portion of the branch. The greatest 

 length of an internode was 5 cm. as contrasted with 4 cm. in the 

 normal. It is thus to be seen that the excessive elongation of the stem 



Fig. 121. ^uercus sp. Transverse section of etiolated petiole. 



was due chiefly to the multiplication and development of the inter- 

 nodes. The stipules were excessively lengthened and were persistent. 



Fig. 122. ^uercus sp. Partial transverse section of terminal portion of etiolated 

 stem. ^, epidermis. Z>, collenchyma. C, cortex. 



The epidermis of the terminal portion of the stem was more or 

 less thickened, and the hypodermal elements were also more col- 

 lenchymatous than is shown by most etiolated forms. No differentia- 



