Chap. XVII. ABSOKPTION BY THE QUADEIFIDS. 413 



plasm, or by its subsequent absorption and transference 

 to other parts of the plant. It will hereafter be seen 

 that in three or four other species of Utricularia the 

 quadrifid processes in contact with decaying animals 

 likewise contained aggregated masses of protoplasm. 



On the Ahsorption of certain Fluids hy the Quadrifid 

 and Bifid Processes. — These experiments were tried to 

 ascertain whether certain fluids, which seemed adapted 

 for the purpose, would produce the same effects on 

 the processes as the absorption of decayed animal 

 matter. Such experiments are, however, troublesome ; 

 for it is not sufficient merely to place a branch in 

 the fluid, as the valve shuts so closely that the fluid 

 apparently does not enter soon, if at all. Even when 

 bristles were pushed into the orifices, they were in 

 several cases wrapped so closely round by the thin 

 flexible edge of the valve that the fluid was appa- 

 rently excluded ; so that the experiments tried in this 

 manner are doubtful and not worth giving. The best 

 plan would have been to puncture the bladders, but 

 I did not think of this till too late, excepting in a few 

 cases. In all such trials, however, it cannot be ascer- 

 tained positively that the bladder, though translucent, 

 does not contain some minute animal in the last stage 

 of decay. Therefore most of my experiments were 

 made by cutting bladders longitudinally into two ; the 

 quadrifids were examined with No. 8 of Hartnack, 

 then irrigated, whilst under the covering glass, with 

 a few drops of the fluid under trial, kept in a damp 

 chamber, and re-examined after stated intervals of 

 time with the same power as before. 



Four bladders were first tried as a control experiment, in 

 the manner jnst described, in a solution of one part of gum 

 arable to 218 of water, and two bladders in a solution of one 

 part of sugar to 437 of water; and in neither case was any 



