THE MOVEMENTS AND HABITS OF PLANTS. 37 



These hairs have broad bases, and their tips are formed 

 by a separate cell. They are absent in the lower part of 

 the utricle where the papilla? abound. The neck is like- 

 wise lined throughout its whole length with transverse 

 rows of long, thin, transparent hairs, having broad bulb- 

 ous bases, with similarly constructed sharp points. They 

 arise from little projecting ridges, formed of rectangular 

 epidermic cells. The hairs vary a little in length, but 

 their points generally extend down to the row next be- 

 low ; so that, if the neck is split open and laid flat, the 

 inner surface resembles a paper of pins — the hairs repre- 

 senting the pins, and the little transverse ridges repre- 

 senting the folds of paper through which the pins are 

 thrust. These rows of hairs are indicated in the previous 

 figure by numerous transverse lines crossing the neck. 

 The inside of the neck is also studded with papillae ; 

 those in the lower part are spherical and formed of four 

 cells, as in the lower part of the utricle ; those in the 

 upper part are formed of two cells, which are much elon- 

 gated downward beneath their points of attachment. 

 These two-celled papillae apparently correspond with the 

 bifid process in the upper part of the bladders of Utricu- 

 laria. The narrow transverse orifice is situated between 

 the bases of the two spiral arms. No valve could be 

 detected here, nor was any such structure seen by Dr. 

 Warming. The lips of the orifice are armed with many 

 short, thick, sharply pointed, somewhat incurved hairs 

 or teeth. 



The two projecting edges of the spirally-wound lamina, 

 forming the arms, are provided with short incurved hairs 

 or teeth, exactly like those on the lips. These project 

 inward at right angles to the spiral line of junction be- 

 tween the two edges. The inner surface of the lamina 

 supports two-celled, elongated papilla?, resembling those 



