368 PINGUICULA VULGARIS. Chap. XVI. 



CHAPTEK XYl. 



PlXGUICrLA. 



Tinguicula vulgaris — Strticture of leaves — Number of insects and 

 other objects caught — Movement of the margins of the leaves — 

 Uses of this movement — Secretion, digestion, and absorption — 

 Action of the secretion on various animal and vegetable substances 

 — The effects of substances not containing soluble nitrogenous 

 matter on the glands — Pinguicula grandiflora — Finguicida hi-si- 

 tanica, catches insects — Movement of the leaves, secretion and 

 digestion. 



Pinguicula vulgaris. — This plant grows in moist 

 places, generally on mountains. It bears on an average 

 eight, rather thick, oblong, light green leaves, having 

 scarcely any footstalk. A full-sized leaf is about H 

 inch in length and J inch in breadth. The young 

 central leaves are deeply concave, and project upwards ; 

 the older ones towards the outside are flat or convex, 

 and lie close to the ground, forming a rosette 

 from 3 to 4 inches in diameter. The margins of the 

 leaves are incurved. Their upper surfaces are thickly 

 covered with two sets of glandular hairs, differing in 

 the size of the glands and in the length of their 

 pedicels. The larger glands have a circular outline as 

 seen from above, and are of moderate thickness ; they 

 are divided by radiating partitions into sixteen cells, 

 containing light-green, homogeneous fluid. They are 

 supported on elongated, unicellular pedicels (contain- 

 ino- a nucleus with a nucleolus) which rest on slight 

 prominences. The small glands differ only in being 

 formed of about half the number of cells, containing 

 much paler fluid, and supported on much shorter pedi- 

 cels. Near the midrib, towards the base of the leaf, the 



