Chap. XVI.] PINGUICULA LITSITANICA. 310 



closely inflected for 72 hrs., showing how much more enduring is 

 the eliect of albumen than of spinach leaves or cabbage seeds. 



(6) A row of small fragments of glass was laid along one 

 margin of a leaf; no efl'ect was produced in 2 hrs. 10 m., but 

 after 3 hrs. 25 m. there seemed to be a trace of inflection, and this 

 was distinct, though not strongly marked, after G hrs. The glands 

 in contact with the fragments now secreted more freely than be- 

 fore; so that they appear to be more easily excited by tlie pressure 

 of inorganic objects than are the glands of Pinguicula vulgaris. 

 The above slight inflection of the margin had not increased after 

 24 hrs., and the glands were now beginning to dry. The surface 

 of a leaf, near the midrib and towards the base, was rubbed and 

 scratched for some time, but no movement ensued. The long hairs 

 which are situated here were treated in the same manner, with no 

 eflFect. This latter trial was made because I thought that the hairs 

 might perhaps be sensitive to a touch, like the filaments of Dionsea. 



(7) The flower-peduncles, sepals and petals bear glands in gen- 

 eral appearance like those on the leaves. A piece of a flower- 

 peduncle was therefore left for 1 hr. in a solution of one part of 

 carbonate of ammonia to 437 of water, and this caused the glands 

 to change from bright pink to a dull purple colour; but their 

 contents exhibited no distinct aggregation. After 8 hrs. 30 m. 

 they became colourless. Two minute cubes of albumen were placed 

 on the glands of a flower-peduncle, and another cube on the glands 

 of a sepal; but they were not excited to increased secretion, and 

 the albumen after two days was not in the least softened. Hence 

 these glands apparently differ greatly in function from those on 

 the leaves. 



From the foregoing observations on Pinguicula lusitanica 

 we see that the naturally much incurved margins of the 

 leaves are excited to curve still farther inwards by coA.tact 

 with organic and inorganic bodies; that albumen, cabbage 

 seeds, bits of spinach leaves, and fragments of glass, cause 

 the glands to secrete more freely; that albumen is dissolved 

 by the secretion, and cabbage seeds killed by it; and lastly 

 that matter is absorbed by the glands from the insects which 

 are caught in large numbers by the viscid secretion. The 

 glands on the flower-peduncles seem to have no such power. 

 This species differs from Pinguicula vulgaris and grandiflora 

 in the margins of the leaves, when excited by organic bodies, 

 being inflected to a greater degree, and in the inflection 

 lasting for a longer time. The glands, also, seem to be more 

 easily excited to increased secretion by bodies not yielding 

 soluble nitrogenous matter. In other respects, as far as my 

 observatiqns serve, all three species agree in their functional 

 powers. 



