THE ASCENDING SAP 



109 



Photo by} 



FIG. 143. -SMALL BLADDEBWOBT (Utricularia minor). 



\_E. Step. 



A portion of the plant is shown natural size. The pitchers are about one-twelfth of an inch long, and are on 

 short stalks. Widely distributed. 



in the North, of England, while other species are found in different parts of 

 the United Kingdom. Pinguicula is a Latin word, a diminutive of pinguis 

 (fat) ; and the name has been given to the genus because its leaves are 

 greasy to the touch. Like the Droseras, Dioncea, and Drosophyllum, all the 

 Butterworts are fly-catchers and fly-digesters ; and the large circular glands, 

 supported upon foot-stalks of varying lengths, which thickly cover the 

 upper surface of the leaves, are the fatal traps. The incurved leaf edges 

 are devoid of glands, and appear to serve the double purpose of prevent- 

 ing insects from being washed away by the rain and of retaining the 

 secretion, which might otherwise flow off the leaf and get wasted. When 

 an insect alights or is blown on the leaf, "it gets entangled in the sticky 

 secretion, and it is killed, and speedily killed, by the secretion adhering to 

 and closing up the spiracles by which the insect breathes" (Sanderson). 



Perhaps it is hardly to be wondered at that the Pinguiculas, like the 

 Droseras, have connections outside their own immediate family. The Butter- 

 worts and the Bladderworts are, in fact, first-cousins ; and who has not heard 

 of the carnivorous doings of the latter? Our illustration shows the Common 

 or Greater Bladderwort ( Utricularia vuigaris), an inhabitant of ditches and 

 deep pools (figs. 140, 142). The plant is common enough in this country. 

 Notice carefully the many little bladders attached to the leaves, a character- 

 istic of all the Utricularias. These bladders are of curious structure. Each 

 has an aperture closing with an elastic valve, which is of much thinner 

 texture than the vesicle to which it is attached. It opens inwards, and 



