67 



the (lci)ressions. This constant irritation of the cuticle at 

 this one point deepened the color and retained it, wlien 

 every other part of the jietal was transmuted by chemical 

 agency to a Hame-like hue I Of course the prominent, 

 black honey guides are of no value as real guides, they 

 serve to decorate the petal and that is all ; and this is all 

 that half of the spots or guides are good for I 



They may, however, l)c of some utility for a purpose to 

 be referred to later. 



Example 12. — Llriodendron Tuhpifera, Tulip-tree, is a 

 stately tree, bearing cup-shaped, green flowers encircled on 

 the inside with a remarkably rich orange band, which color 

 strikes through to the outside. 



The flowei" is two inches across, with long stamens reach- 

 ing nearly to the U)\) of the six upright petals, and its three 

 sepals, (juite similar in size and shape, but lacking the 

 orange color, become strongly declined. 



The general appearance of the tlower is that of a tulip, 

 and the orange band recalls a similar band in the garden 

 variety of tulip, before referred to, though differing in tint. 

 When I first examined the tlower 1 innnediately remarked 

 that the orange band was low down in the tlower, while 

 according to my theory it ought to be directly opjjosite the 

 anthers, so that the bee, as in the case of the tulij) and 

 [)oppy, would come directly in contact with the spot or 

 marking on the petal ; this clearly was not the case in 

 Liriodendron, and for a moment I was j)uzzled. I was 

 able, however, shortly to discover the reason of this differ- 

 ence. One cannot examine the actions of insects quite so 

 handily on a tall tree as he might wish, but happily there 

 were a few low branches and I was not obliged to clinib it. 

 Greatly to my surprise the bees flew right past the anthers 

 into the space between the stamens and the orange band, 

 and instead of facing the anthers, they faced the petal and 

 confined themselves strictly to the orange zone, not going 

 above or below it ! All the surface of this zone they dili- 



