Chap. XVII. DEVELOPMENT OF THE BLADDEKS. 425 



simple elongated cells, runs up the short footstalk, 

 and divides at the base of the bladder. One branch 

 extends up the middle of the dorsal surface, and 

 the other up the middle of the ventral surface. In 

 full-grown bladders the ventral bundle divides close 

 beneath the collar, and the two branches run on each 

 side to near where the corners of the valve unite with 

 the collar ; but these branches could not be seen in 

 very young bladders. 



The accompanying figure (fig. 23) shows a section, 

 which happened to be strictly medial, through the foot- 

 stalk and between the nascent antennae of a bladder 

 of Utricularia vulgaris, -p^ inch 

 in diameter. The specimen was 

 soft, and the young valve be- 

 came separated from the collar 

 to a greater degree than is 

 natural, and is thus represented. 

 We here clearly see that the 

 valve and collar are infolded 

 prolongations of the walls of the 

 bladder. Even at this early 

 age, glands could be detected 

 on the valve. The state of the 

 quadrifid processes will presently 

 be described. The antennte at this 

 period consist of minute cellular projections (not shown 

 in the above figure, as they do not lie in the medial 

 plane), which soon bear incipient bristles. In five 

 instances the young antennae were not of quite equal 

 length; and this fact is intelligible if I am right in 

 believing that they represent two divisions of the 

 leaf, rising from the end of the bladder; for, with 

 the true leaves, whilst very young, the divisions are 

 never, as far as I have seen, strictly opposite; they 



Fig. 23. 



{Utricularia vulgaris.) 



Longitudinal section through 



a young bladder, -^ of an inch 



in length, with the orifice too 



widely open. 



