Chap. XVII.] DEVELOPMENT OF THE BLADDERS. 345 



ders appeared as if formed by the oblique folding over of the 

 apex and of one margin with a prominence, against the op- 

 posite margin. The circular hollow between the infolded 

 apex and infolded prominence apparently contracts into the 

 narrow orifice, wherein the valve and collar will be developed ; 

 the bladder itself being formed by the confluence of the op- 

 posed margins of the rest of the leaf. But strong objections 

 may be urged against this view, for we must in this case sup- 

 pose that the valve and collar are developed as symmetrically 

 from the sides of the apex and prominence. Moreover, the 

 bundles of vascular tissue have to be formed in lines quite 



Fig. 24. 



( Utricularia vulgarvt.) 



Toang leaf from a winter bud, showing on the left side a bladder in its 



earliest stage of development. 



irrespective of the original form of the leaf. Until grada- 

 tions can be shown to exist between this the earliest state 

 and a young yet perfect bladder, the case must be left doubt- 

 ful. 



As the quadrifid and bifid processes offer one of the 

 greatest peculiarities in the genus, I carefully observed their 

 development in Utricularia neglecta. In bladders about ^iv 

 of an inch in diameter, the inner surface is studded with 

 papillse, rising from small cells at the junctions of the larger 

 ones. These papillaj consist of a delicate conical protuber- 

 ance, which narrows into a very short footstalk, surmounted 



