464 SEMI-CENTENNIAL OF TORREY BOTANICAL CLUB 
least by shrinkage. Similar clefts are found in Piaropus. The 
three spreading segments of the lower lip form a convenient landing 
platform for smaller insects. The three segments of the upper 
lip are rather erect and form a sort of standard with a conspicuous 
mark on the posterior petal-segment which has been regarded as a 
nectar-guide for insects, a large double blotch of bright yellow— 
rarely two separate spots as often described, at least in plants from 
several regions examined by the writer. The yellow pigment is 
located in a layer of cells immediately underneath the inner epider- 
mis, and appears to be diffused in the cytoplasm of these cells; 
they extend outward in irregular scallops on the periphery of the 
spot, producing a border slightly more greenish in tint, hardly 
perceptible to the eye, but noticeable in photographs made with a 
color-screen too light to bring out the correct value of ‘the main 
part of the spot (PLATE 14). Except in the region of this yellow 
blotch, the cells of both the inner and the outer epidermis show a 
rather violet-blue pigment dissolved in the cell-sap, and in addition 
each cell contains a conspicuous globule of a clear indigo-blue 
color, consisting either of solid amorphous anthocyanin or possibly 
of a tannin or protein substance impregnated with pigment.* 
In the lower part of the perianth tube the blue color is 
lacking and some chlorophyl may be present, but examination 
with a lens reveals pink spots due to single large subepidermal 
cells containing a pigment dissolved in the cell-sap, of a slightly 
purplish-red tint and having an acid reaction. Similar hypo- 
dermal cells are found throughout the pistils, where they also 
contain red pigment at least in the short-styled form (FIG. 8). 
In the middle and upper regions of the perianth, where the epider- 
mal cells are blue, much larger scattered hypodermal cells occur 
in abundance (FIG. 2) but when dissected out, these are found to 
be colorless; to assume, however, that anthocyanin is absent from 
* When the cells are treated with дава acid and osmic acid (employed 
as a tannín test) this deep blue globule turns to a wine-red color, and the dissolved 
зимнина moy ue pent pine] in small ‘lobes p the same сою. M сотне 
cyanin shows the same tint. Sucha contention of ед і solid ее 
was first described and figured іп Са by Hildebrand in 1863, but has been 
mentioned since Borm 1906, when Gertz in his important work Studier öfver Pic 
cyan reported the wide occurrence of such a condition; summarized in Miss Whel- 
dale's book, The Anthocyanin Pigments of Plants 32-35. 1016. 
