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Show 394 PINGUICULA LUSITANIOA. CHAP. XVI. (7) The flower-peduncles, sepals and petals, bear ?land~ in general appearance like those on the leaves. A piece of a fiower-pflduncle 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. 30m. they became colourless. Two minute cubes of albumen were placed on the glands of a flowerpeduncle, 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 tbe 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 contact with organic and inorganic bodies; that albu1nen, 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 Inatter 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 fro1n Pingtticala vulgaris and grandijlora 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 observations serve, all three species agree in their functional powers. CHAP. XVII. UTRIOULARIA NEGLEOTA. 395 CHAPTER XVII. U TB.ICl"LARIA. Utricularia neglecta-Structure of the bladder-rrhe uses of the several parts-Number of imprisoned animals-Manner of captureThe bladders cannot digest animal matter, but absorb the products of its decay-· Experiments on the absorption of certain fluids by the quadrifid processes-:- Absorption by the glands- Summary of the observation on absorption- Development of the bladdersUtricularia v·ulga1is- Utricularia minor- Utricularia clandestina. I WAS led to investigate the habits and structure of the species of this genus partly from their belonging to the same natural family as Pinguicula, but more especially by Mr. Holland's statement, that "water insects are often found imprisoned in the bladders," which he suspects " are destined for the plant to feed on."* The plants which I first received as Utrir:1daria vulgaris from the New Forest in Hampshire and from Cornwall, and which I have chiefly worked on, have been determined by Dr. Hooker to be a very rare British species, the Utricularia neglecta of Lehm.t I subsequently received the true Utricularia vulgaris from Yorkshire. Since drawing up the following description from my own observations and those of my son, Francis Darwin, an important memoir by Prof. Cohn .* The ' Quart. Mag. of the H1gh Wycombe Nat. Hist. Soc.' July 1868, p. 5. Delpino (' Ult. Osservaz. sulla Dicogamia,' &c. 1868-1869, p. 16) also quotes Crouan as having found (1858) crustaceans within the blndders of Utricularia vulgaris. t I am much indebted to the Rev. H. M. Wilkinson, of Bistern, for having sent me several fine lots of this species from the New Forest. Mr. Ralfs was also so kinc.l as to send me living plants of the same species from near Penzance in Corn wall. |