Chap. XVIII.] STRUCTURE OP THE LEAVES. 



363 



mens were broken; nor does it appear that Dr. Wanning 

 ascertained this point. 



So much for the external structure. Internally the lower 

 part of the utricle is covered with spherical papillae, formed 

 of four cells (sometimes eight ac- 

 cording to Dr. Warming), which evi- 

 dently answer to the quadrifid pro- 

 cesses within the bladders of Utri- 

 cularia. These papillae extend a 

 little way up the dorsal and ventral 

 surfaces of the utricle; and a few, 

 according to Warming, may be found 

 in the upper part. This upper region 

 is covered by many transverse rows, 

 one above the other, of short, closely 

 approximating hairs, pointing down- 

 wards. These hairs have broad bases, 

 and their tips are formed by a sepa- 

 rate cell. They are absent in the 

 lower part of the utricle where the 

 papillae abound. The neck is like- 

 wise lined throughout its whole length 

 with transverse rows of long, thin, 

 transparent hairs, having broad bulb- 

 ous (Fig. 30) bases, with similarly con- 

 structed 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 Portion of inside of neck 

 below; so that if the neck is split open leading into the utricle, 

 and laid flat, the inner surface resem- 

 bles a paper of pins, the hairs repre- 

 senting the pins, and the little trans- 

 verse ridges representing the folds of 

 paper through which the pins are thrust. These rows of 

 hairs are indicated in the previous figure (29) 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 ; thoee in the upper part a|p formed of two cells. 



Fig. 30. 

 (Genlisea omata.) 



greatly enlarged, show- 

 ing the downward 

 pointed bristles, and 

 small quadrifid cells or 

 processes. 



