140 MICROSCOPICAL COLLECTIONS IN FLORIDA. 



The Pinguicula, another of the insectivorous plants, is found 

 abundantly on the more open plains, and not far from wet places. 

 It is a compact rosette of very light green leaves, growing close 

 to the ground, from the center of which rises a single flower- 

 stalk, eight or ten inches high. The leaves have their edges 

 turned up, forming a shallow trough, and on the upper surface 

 are mushroom glands, which exude a viscid secretion. Insects 

 are caught and held by this sticky substance until they die. The 

 nutritious matter is then dissolved out by an acid secretion, and 

 is ultimately absorbed into the substance of the plant by the 

 glands on the leaf. The edge of a leaf when excited by a cap- 

 ture will bend over upon it for a short time, for the purpose of 

 more effectually securing it, and of bathing it in the secretions. 

 The calyx and flower-stalk, as I have already mentioned, are 

 thickly covered with the same mushroom glands that are found 

 more sparingly on the leaves. I have never seen any evidence 

 that the flower appendages took any part in the digestion of 

 insects. They seem to be rather in the nature of an ornamenta- 

 tion than of anything useful. For exhibition, therefore, or for 

 double-staining, the calyx and flower stem will be found by far 

 the most attractive part of the plant. The best way to preserve 

 them, as well as all such small material, until wanted for use, is 

 to put them green into a common morphia vial with a few drops 

 of alcohol and water, and then to cork and seal them up tight 

 with melted beeswax. To prepare them for the slide these ob- 

 jects may be treated precisely as recommended for sections of 

 castor-oil plant, but should be mounted in a weak solution of 

 glycerine in camphorated water. 



If cells are made of rings punched out of the thin sheets of 

 colored wax, used by artificial flower makers, and then coated 

 with either liquid marine glue, or a mixture in equal parts of 

 gold size and gum dammar dissolved in benzole, this method of 

 liquid mounting may be as easily and safely performed as mount- 

 ing in balsam. In very many cases simple water, made antiseptic 

 in any manner, will be found far preferable to any other media, 

 both for retaining the full and distended forms of minute organs, 

 and for bringing out the delicate markings of vegetable structure 

 which the highly refractive balsam would entirely obliterate. 



