Chap. XVII.] DEVELOrMENT OP THE BLADDERS. 343 



more quickly than the processes; as these latter remain in 

 permanent contact with captured and decaying animals. 



Finally, the conclusion to which we are led by the fore- 

 going experiments and observations is that the bladders have 

 no power of digesting animal matter, though it appears that 

 the quadrifids are somewhat affected by a fresh infusion of 

 raw meat. It is certain that the processes within the blad- 

 ders, and the glands outside, absorb matter from salts of 

 ammonia, from a putrid infusion of raw meat, and from 

 urea. The glands apparently are acted on more strongly by 

 a solution of urea, and less strongly by an infusion of raw 

 meat, than are the processes. The case of urea is particular- 

 ly interesting, because we have seen that it produces no 

 effect on Drosera, the leaves of which are adapted to digest 

 fresh animal matter. But the most important fact of all is, 

 that in the present and following species the quadrifid and 

 bifid processes of bladders containing decayed animals gen- 

 erally include little masses of spontaneously moving proto- 

 plasm; whilst such masses are never seen in perfectly clean 

 bladders. 



Development of the Bladders. My son and I spent much 

 time over this subject with small success. Our observations 

 apply to the present species and to Utricularia vulgaris, but 

 were made chiefly on the latter, as the bladders are twice as 

 large as those of Utricularia neglecta. In the early part of 

 autumn the stems terminate in large buds, which fall off and 

 lie dormant during the winter at the bottom. The young 

 leaves forming these buds bear bladders in various stages of 

 early development. When the bladders of Utricularia vul- 

 garis are about ihs inch (.254 mm.) in diameter (or rhs in 

 the case of Utricularia neglecta), they are circular in out- 

 line, with a narrow, almost closed, transverse orifice, leading 

 into a hollow filled with water; but the bladders are hollow 

 when much under rm of an inch in diameter. The orifices 

 face inwards or towards the axis of the plant. At this early 

 age the bladders are flattened in the plane in which the 

 orifice lies, and therefore at right angles to that of the ma- 

 ture bladders. They are covered exteriorly with papillae of 

 different sizes, many of which have an elliptical outline. A 

 bundle of vessels, formed of simple elongated cells, runs up 

 the short footstalk, and divides at the base of the bladder. 



