viii] TURIONS OF BLADDERWORTS loi 



The Bladderworts are able to reproduce themselves success- 

 fully for long periods without having recourse to flowering and 

 fruiting. Utricularia intermedia^ for instance, was observed in 

 a certain district in Germany to propagate itself for years by 

 vegetative means, when the ditches in which it lived were cleared 

 too frequently to give it an opportunity of flowering i. The 

 organs of vegetative reproduction the turions or winter-buds ^ 

 are spherical or egg-shaped bodies developed at the ends 

 of the shoots. The case of Utricularia vulgaris may be taken as 

 typical. In this species turion formation takes place, in normal 

 circumstances, between the beginning of August and the 

 middle of November. The apical region of the shoot produces 

 a number of reduced leaves separated by highly abbreviated 

 internodes. The concave leaves cover one another in imbricate 

 fashion and are closely packed into a firm ball, clothed with a 

 protective layer of mucilage. When the plant is grown in an 

 aquarium, water-snails are its chief enemies, but the winter-buds, 

 with their coat of hairs and slime, seem immune from the depre- 

 dations of these creatures^. The parent plant sinks to the bottom 

 in the autumn, owing to its tissues becoming water-logged, and 

 carries the turions with it. These, in spite of their firm texture, 

 are lighter than water, and, but for their attachment to the 

 decaying axis, would rise to the surface like pieces of cork. As 

 it is, they remain all through the winter stationary at the bottom, 

 but with their apices directed upwards. In the spring, the 

 turion is at last able to rise to the surface the parent axis 

 having been reduced by months of rotting to little more than 

 a string-like vascular cylinder, which often adheres persistently 

 to the base of the winter-bud. The axis of the turion elongates 

 with remarkable rapidity, attaining three to six times its ori- 

 ginal length. The composition of the bud then becomes mani- 

 fest; a number of bud-scales occur at the base, followed by 

 several transition leaves and then normal foliage leaves which 



iSchultz, F. (1873). 



2 Benjamin, L. (1848), Gluck, H. (1906), etc. 



^ Meister, F. (1900). 



