MICROSCOPICAL COLLECTIONS IN FLORIDA. 139 



danger will be in over-staining; therefore, after decolorizing and 

 immersing for a few hours in the carmine solution, the specimens 

 should be exposed to only a very weak fresh solution of logwood 

 for fifteen or twenty minutes. If the anilin blue is resorted to 

 at all, it must be in a very weak solution. A mounting of a leaf 

 and a stem with flower buds in one cell in camphorated or carbo- 

 lated water, makes a very pretty and complete slide for the 

 Drosera. 



The Utricularja is a floating carnivorous plant which grows in 

 the shallow water of quiet ponds. On the surface of the water 

 from five to seven leaves are spread out like the spokes of a 

 wheel, and from the center of these leaves the plant sends up- 

 ward its flower stalk and downward its root-like branches, floating 

 freely in the water. Among the thickly branching fibres of these 

 long submerged stems, are perched innumerable little bladders or 

 utricles, not much larger than the head of a pin, each provided 

 with a mouth at the bottom of a sort of funnel of bristles, 

 closed with a cunning little trap lid which opens inward, engulf- 

 ing and imprisoning whatever minute creatures or substances 

 may happen to be resting on it. In these sacks during the grow- 

 ing season, we will find numerous microscopic water fleas, mites 

 and beetles, with grains of pine pollen and other floating parti- 

 cles. The organic bodies will be found in all stages of digestion, 

 showing that the plant derives nourishment from such captured 

 prey ; and apparently its only means of livelihood is trapping. 



When taken from the water and dried under slight pressure, 

 the submerged portions of the Utricularia will be found literally 

 covered with diatoms; and many very interesting chrysalids of 

 water-insects will be found attached to them. These will all be 

 washed off if the plant is bleached in chlorinated soda. To pre- 

 serve them it will be necessary to remove the color in alcohol, 

 and besides to handle very carefully. The staining can only be 

 single ; and I have found a weak solution of eosin in water, to 

 be the best material for coloring, showing at the same time the 

 structure of the utricles and the captures contained in them. 

 Specimens of new growths, showing the just forming utricles 

 and the peculiar circinate mode of growth, should be included 

 on the slide. The mounting should be in camphorated water. 



