298 PINGUICULA VULGARIS. [Chap. XVL 



CHAPTER XVI. 



PINGUICULA. 



Pinguicula vnlgarM Rtructnre of leaves Number of insects and other 

 objects ciiuglit Movement of the margins of the leaves Uses of this 

 movement Secretion, digestion, and absorption Action of the secre- 

 tion on various animal and vegetable subsfcinces The ettects of sub- 

 stances not contjiining soluble nitrogenous matter on the glands 

 PingiiicHia grandiflora Pinguicula lusitanica, catches insects Move- 

 ment 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 li inch in length 

 and i 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; form- 

 ing 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, homo- 

 geneous fluid. They are supported on elongated, unicellular 

 pHxliccls (containing 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 pedicels. 

 Near the midrib, towards the base of the leaf, the pedicels 

 are multicellular, are longer than elsewhere, and bear smaller 

 glands. All the glands secrete a colourless fluid, which is 

 so viscid that I have seen a fine thread drawn out to a length 



[According to Bntnlin plants grown In shndy places. It 



(* Flora,' 18(7) the yellowish- Is due to a yellow homogencons 



green colour Is peculiar to plants substance found In the epTdorraal 



grown In strong light, being re- cells aud In the glands. F. D.] 

 placed by a more lively green in 



