Woodhead : Notes on the Bluehell. 



47 



salt solution, or other reagent which will reduce turg-idity or 

 destroy the protoplasm, they elongate.''^" These features may be 

 easily observed in the bluebell. Transverse sections through 

 the contracted part of a root, preserved in alcohol, are shown 

 (Plate III., 5 and 6) ; if these are compared with Fig-. 5, b 

 and c, the shortening of these cells as well as the numerous 

 wrinkles of the walls are well seen. In consequence of these 

 changes the cortical cells, while elongating transversely, shorten 

 longitudinally, and this region of the root, from one to three 

 inches, becomes much contracted. The vascular tissues are also 

 passively involved, and become shortened and bent (Fig. 6, a). 



Fig. 6, a, loiigfitudinal section through base of bulb and upper reg-ion of contractile rcot, 

 showinof absciss layer, X25 ; b, a few cells of absciss layer enlarged, x 150; c, section through 

 a root scar showing formation of cork, X 25 ; d, a few of these cells enlarged, X 150. 



The lower portion of the root, often four to five inches in length, 

 being firmly fixed in the soil, the contraction of the upper region 

 results in the bulb being pulled more deeply underground.! In 

 the middle of May many such bulbs were found, and the con- 

 tractile region measured three quarters of an inch. Roots were 



" Sachs, Arbeiten des botan. Inst., Wurzburg-, I, p. 419 ; also Physiology 

 of Plants, En§:l. Trans., 1887, p. 576. 



t Scott, Flowering- Plants, p. 196. 

 1904 Februarj' i. 



