THE ORIGIN OF FLOWERS. 



157 



as a bait to draw the insect fertilizer, and as a 

 security against his breaking in upon the tissues 

 themselves. This juice is what we know as honey. 

 Many parts of plants contain small quantities of 

 sugar, and in some (like the sugar-cane and the 

 American maple) it exists in large proportions 

 in the sap; but wherever we find it deposited in 

 the concentrated form of honey, we may be sure 

 that the plant has distilled it for some special 

 purpose of attraction. Honey-glands sometimes 

 occur on the stem, in which case they are often 

 mere traps to attract the presence of ants, who 

 act as guards to the plant against the approach 

 of noxious insects. But more commonly they are 

 to be found in the flower ; that is to say, some- 

 where among the whorls of stunted leaves which 

 surround the seed-producing structures. There 

 they are set as insect-attractors, to draw the fer- 

 tilizing agents into the neighborhood of the pol- 

 len and the ovules. Of course we can only sup- 

 pose that this production of special honey-secret- 

 ing organs proceeded very slowly during long 

 ages, parallel with the development of specialized 

 honey-seeking insects. And we have some war- 

 rant for the belief — more fully to be set forth in 

 a subsequent paragraph — that some of the great- 

 est honey-storing plants are quite modern deni- 

 zens of our earth, and owe their existence to the 

 general demand for sweet-stuffs among their in- 

 sect contemporaries. Similarly, we have reason 

 to think that the honey-eaters have gone on 

 adapting themselves more and more continuously 

 to the flowers, until at last, in the fullness of time, 

 we get such specialized creatures as hive-bees 

 and humming-birds. But perhaps the most notice- 

 able fact of all is this — that the very same sweet 

 juice which was developed to suit the taste of 

 humble-bees and emperor-moths is the symbol 

 for sweetness in the language of mankind, whose 

 tastes have been formed upon the strawberry, the 

 plum, and the banana. And is it not likewise 

 significant of the same general community of 

 nervous impressibility that while the humming- 

 birds, belonging to a mainly fruit-eating class, 

 have taken to the honey of bignonia and hibis- 

 cus, the wasps, in turn, belonging to a mainly 

 honey-eating class, have taken to the sugary 

 juices of the peach and the nectarine ? I think 

 these facts . may guide us greatly when we come 

 to ask how the love of color has been devolved in 

 the human race. 



Secondly, as to smell. So soon as flowers have 

 developed the honey-producing structures, they 

 will gain an advantage by giving insects at a dis- 

 tance some warning of their presence. There is 



no simpler way of doing this than by means of 

 etherialized particles, which may chemically affect 

 some exposed nervous structure in the insect; 

 and such chemically affected structures are what 

 we know as organs of smell. Here, too, we see 

 the same essential agreement between the higher 

 and lower forms of animal life ; for just as our 

 taste for sweets corresponds to the insect's taste 

 for honey, so our love for the perfume of flowers is 

 absolutely identical with the pleasure which draws 

 the butterfly toward the luscious blossoms of the 

 tuberose and the stephanotis. In our own Eng- 

 lish meadows we may see the bees and the chil- 

 dren alike collected around the fragrant meadow- 

 sweet, or seeking together for the scented clover. 

 And it is worth while to observe that most of the 

 sweet-smelling flowers appear to be quite late 

 developments of vegetable life, a fact which har- 

 monizes well with the correspondingly late devel- 

 opment of the bees and other highly-adapted 

 honey-suckers. There is no tribe of plants, for 

 example, more noticeable for their perfume than 

 the family of Labiates. To this family belong the 

 various kinds of mint, thyme, balm, sage, marjo- 

 ram, lavender, rosemary, horehound, and cala- 

 mint, besides innumerable foreign or little-noticed 

 species, like patchouli, hyssop, and basil. These 

 plants are almost all very peculiarly shaped and 

 highly scented, and their attractiveness for bees 

 has become proverbial — the honey of poetry is 

 always " redolent of thyme." Now the Labiates, 

 so far as known, are late tertiary plants ; that is 

 to say, they made their first appearance upon 

 earth only a short period before the advent of 

 man himself. In short, it was not until bees and 

 other specialized honey-suckers had reached a 

 high point of development that scented flowers 

 began to possess any advantage over their neigh- 

 bors. I shall endeavor to show in a future paper 

 that our chief fruit-bearers, the Rosacea, are 

 similarly late in making an appearance on the 

 earth, and that they owe their evolution to the 

 higher birds and frugivorous mammals who began 

 to exist in large numbers about the same period. 

 For the present it will be sufficient to point out 

 the intimacy of the interdependence which we 

 thus see to exist between the evolution of the 

 animal and vegetable worlds. 



It is needful, too, to point out another special 

 case of the sense of smell. While the flower- 

 sucking insects have likes and dislikes, in taste 

 and smell, essentially identical with those of man, 

 the descendant of frugivorous ancestors, and with 

 those of the flower-sucking humming-birds, and 

 the fruit-eating birds and mammals, there is an- 



