66 THE POPULAR SCIENCE MONTHLY. 



all is helmet-shaped, and it forms the curious cowl which gained the 

 plant its suggestive name from our mediaeval ancestors. The two 

 side sepals, to right and left, are flatter and straighter, but very broad, 

 while the two lowest of all are comparatively small and narrow. The 

 whole five are bright blue in color. Pull off these petal-like sepals, 

 and you come to the real petals beneath them. At first you can hardly 

 find them at all ; you see only two long blue horns, covered till now 

 by the helmet-shaped upper sepal or cowl, and each with a queer cup- 

 like sac at its extremity, containing a small drop of clear fluid. That 

 fluid is honey, but I should advise you to be careful in tasting it not 

 to bite off any of the flower, for monk's-hood is the plant from which 

 we get the now famous poison, aconitine ; and a very little of it goes 

 a long way. Unlike as they are to the familiar yellow petals of the but- 

 tercup, one can still gather from their position that the two long horns 

 are really petals. But where are the three others ? Well, you must 

 look rather close to find them, and perhaps even then you won't suc- 

 ceed after all ; for sometimes the three lower petals have disappeared 

 altogether, being suppressed by the plant as of no further use to it. 

 In this particular specimen, however, they still survive as mere relics 

 or rudiments, three little narrow blue blades, not nearly as big as a 

 gnat's wing, placed alternately to the lower sepals. As for the sta- 

 mens, they are still present about as numerously as in the buttercup ; 

 whereas the carpels, or fruit-pieces, are reduced to three only, which 

 in the ripe seed-vessels here on the lower and older part of the spike 

 grow into long pods or follicles, each containing several seeds. 



Thus, then, the flower .of monk's-hood agrees fundamentally with 

 the flower of the buttercup ; while, at the same time, it has undergone 

 some very singular and suggestive modifications. In both there are 

 five sepals ; but in the buttercup all five are alike, and all five are 

 greenish ; whereas in the monk's-hood they have acquired different 

 shapes, exactly fitting them to the bee's body, and they have become 

 blue, because blue is the favorite color of bees. Again, in both there 

 are five petals ; but in the buttercup all five are similar and yellow, 

 and all five secrete a drop of honey at the base ; whereas in the monk's- 

 hood two of them have become long and narrow specialized nectaries, 

 while the other three, being no longer needed, have grown obsolete or 

 nearly so. Once more, the stamens remain the same ; but the carpels 

 have been immensely reduced in number, at the same time that the 

 complement of seeds in each has been greatly increased by way of 

 compensation. 



Well, how are we to account for these peculiar modifications ? En- 

 tirely by the action of the fertilizing bees. The secret of the monk's- 

 hood depends, in the first place, upon the fact that its flowers are clus- 

 tered into a spike, instead of growing in solitary isolation at the end of 

 the stem, as in the common buttercups. Now, Mr. Herbert Spencer 

 has pointed out that solitary terminal flowers are always radially sym- 



