lOO 



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^. Eventually the testa becomes 

 thoroughly wetted and the seed sinks. The seedling is unique 

 in structure (Fig. 67). In t/. 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; I, 

 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 ^ 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^. 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). Goebel, K. (1891). 



