1OO 



UTRICULARIA 



[CH. 



the Utricularias than the method of asexual propagation 

 shortly to be described. In the case of Utricularia minor , for 

 instance, ripe seeds are seldom obtained. When they occur, 

 they are found to be well suited to floating on water, as the 

 surface of the seed-coat is pitted and capable of retaining air 

 bubbles for a considerable time 1 . Eventually the testa becomes 

 thoroughly wetted and the seed sinks. The seedling is unique 

 in structure (Fig. 67). In U. vulgaris, which may serve as an 

 example, germination begins in spring at the bottom of the 



FIG. 67. Utricularia vulgaris, L. 

 Geminating seed; s, seed coat; /, 

 primary leaves, (x about 19.) 

 [Adapted from Kamienski, F. 

 (1877)-] 



FIG. 68. Utricularia exoleta, R.Br. 



A and B, stages in germination; 



c ? cotyledons. In A the seed-coat 



is removed. [Goebel, K. (1891).] 



water. The following organs are produced 2 a number (6-12) 

 of simple primary leaves (/ in Fig. 67), a bladder, a conical 

 stem apex, from which the main axis develops laterally, and an 

 adventitious shoot (? an air-shoot). No root appears in the 

 seedling, and there is not even any rudiment of this organ in the 

 embryo 3 . In Utricularia exoleta*^ a small and simple aquatic 

 form found in Asia and tropical Australia, only two primary 

 leaves (? cotyledons) are formed, but this is perhaps to be inter- 

 preted as a case of reduction (Fig. 68). 



1 Meister, F. (1900). 



2 Warming, E. (1874) and Kamienski, F. (1877). 



3 Merz, M. (1897). 4 Goebel, K. (1891). 



