96 UTRICULARIA [CH. 



may remain alive in them for some days 1 . There is no doubt 

 that the bladders are capable of digesting small animals, algae, 

 etc., and, although no enzyme has yet been recognised, the 

 presence of benzoic acid has been demonstrated 2 . Owing to 

 the small size of the bladders, it must obviously be difficult 

 to obtain an adequate quantity of the secretions for investiga- 

 tion. 



FIG. 63. Utricularia minor, L. Part of a 

 shallow- water plant, E= earth-shoot. Two 

 branches marked S at the base of the inflor- 

 escence axis have been cut off. i and 2 = bracts 

 on the inflorescence axis. (Reduced.) [Modified 

 from Gluck, H. (1906), Wasser- und Sumpf- 

 gewachse, Bd. n, PL II, Fig. 18.] 



FIG. 64. Utriculariaminor, 

 L. a, green leaf of normal 

 submerged shoot ; b, colour- 

 less leaf of an earth-shoot. 

 In the latter the leaf seg- 

 ments are reduced to rudi- 

 ments indicated by S. (En- 

 larged.) [After Gluck, H. 

 ( 1 906) , Wasser- und Sumpf- 

 gewachse, Bd. n, Figs. 2 a 

 and b, p. 42.] 



Besides the normal leafy branches, which serve for assimila- 

 tion and also bear bladders, no less than three modified types 

 of vegetative shoot are borne by certain of the European 

 Utricularias the * earth-shoot,' the breathing shoot or ' air- 

 shoot/ and the so-called 'rhizoid 3 .' 



1 Cohn, F. (1875). 2 Luetzelburg, P. von (1910). 



3 Goebel, K. (189 1-1893) and Gluck, H. (1906). 



