324 



SCIENCE 



[Vol. XXI. No. 541 



The molecular rhythm of any organism is necessarily of limited 

 compass. In the embryo only the main chords are struck; the 

 molecular motions are comparatively free, and some amount of 

 modification is then possible. But, as the intervals are filled up 

 by the harmonious motions of the assimilated molecules, the 

 rhythm becomes fuller and, at the same time, more fixed, till a 

 point is reached at which little more permanent assimilation is 

 possible. This is the climacteric of the life of that organism. 

 The limit is determined by the original outlines of the molecular 

 rhythm in the embryo, slightly modified by the amount and the 

 quality of the food assimilated during growth. 



We have now to consider the action of the law of sympathetic 

 vibration on the growing organism. 



A tightly stretched wire may be made to give out a musical 

 note by sounding near to it a certain note on a violin. The group 

 of vibrations produced in the violin is communicated to the air, 

 and the air communicates it to the stretched wire. It can only 

 do this if the condition of the wire is such as to make that group 

 of vibrations possible to it. If only some part of the group is 

 possible to it, it may take up that part and reject the rest. This 

 is a case of molar, not of molecular, vibration, but the same law 

 operates in the case of the molecular vibrations of radiant heat 

 and light, which are communicated through the ether. Such of 

 these vibrations as are possible to some of the molecules of the 

 substance receiving them will be absorbed, while the rest will be 

 transmitted or reflected. The energy of those vibrations which 

 have been absorbed will go to increase the amplitude of the vibra- 

 tions b}^ which they have been assimilated They do not, as in 

 the case of food, introduce fresh molecules with harmonic vibra- 

 tions which occupy vacancies in the established rhythmical sys- 

 tem, but they give increased force to certain existing vibrations, 

 and thus alter the balance of forces in the established system. 

 The vibrations so reinforced will acquire a more or less controlling 

 influence throughout the total group, and there will be a tendency 

 among the vibrations of less enei'gy to fall gradually into the 

 swing of these controlling vibrations. Thus the molecular rhythm 

 of the total group may become modified within certain narrow 

 limits by the light in which the organism lives, if that influence 

 is continued for a sufHciently long period, as well as by the food 

 which it assimilates. 



It is evident that the tendency of the action of these two laws 

 — the law of the concentrating wave and tke law of sympathetic 

 vibration — must be to enhance the energy of the original molec- 

 ular rhythm of the embryo, to make it fuller, richer, more defi- 

 nite, and less capable of further modification as it approaches its 

 climacteric, while, at the same time, it is simplified and cleared 

 of a number of vibrations differing only slightly from the con- 

 trolling ones, by the bringing of these gradually into unison. ' 



The bearing of these results upon organic color remains to be 

 discussed. 



It is a well-known physiological rule, with possibly a few ex- 

 ceptions, that organisms in their embryonic and early stages are 

 less brightly colored than they afterwards become. This is plainly 

 seen in the young of birds. Germinating seeds are nearly always 

 of a dull white, which means that about an equal, though small, 

 quantity of every vibration in the sunlight is able to be absorbed. 

 The color of the first leaves is the primary green, indicating that 

 the plant, while able to absorb a larger proportion of the white 

 light, is becoming less able to absorb the vibrations of medium 

 size. As the foliage becomes developed, varied tints of green, 

 with some reds and dull purples, are reflected, showing that there 

 is a still less varied capacity for absorbing. Finally, in the blos- 

 som of the higher orders of plants, of which the color is nearly 

 always some shade of the brilliant secondary hues, scarlet, orange, 

 yellow, blue, or rose, it is evident that a great simplification of 

 the molecular rhythm has taken place, so that the absorption is 

 chiefly confined to one group of the light-vibrations, while large 

 proportions of the other two are reflected. 



This process of simplification in the molecular Thythm, as the 

 concentrating organic wave approaches its climacteric, may be 

 traced in various phases of vegetable and animal life. In a 

 flowering tree or shrub there are three great systems of structure, 

 viz., the stem and branches, the foliage, and the inflorescence; 



and these represent three stages of advancing development and 

 vitalization. The color reflected by the system which stands 

 lowest in the scale, the stem and branches, is generally dull 

 green, brown, or plum, indicating that nearly all the light which 

 reaches them is absorbed. In the uniform green of the foliage a 

 certain amount of simplification is shown ; and in the brilliance 

 of the inflorescence we see the greatest simplification attainable by 

 that species. 



Those families of plants in each great class which have the 

 lowest organization display, as a rule, the least color. The 

 Coniferse represent the earliest type of existing trees, and are 

 nearly all sombre in coloring. The Amentiferse stand next, and, 

 though brighter in foliage and much more varied, do not attain 

 to colored blossom. The numerous orders of "flowering" trees 

 and shrubs are of most recent origin, and represent the highest 

 phas^f development in the great concentrating wave of vegeta- 

 ble life. The fern form is a very ancient one, and has never, even 

 to the present day, developed much in the way of color. But, if 

 it be true that the recent Monocotyledons are derived from the 

 ferns, they may represent the simplified condition of the fern 

 wave, and among them are many of our most brilliant flowers. 

 The Fungus form must probably be an ancient one also, and 

 among recent Fungi many brilliant hues are developed, which can 

 have no connection with insect choice. 



In the large class of birds, the Ratiije (ostrich, emeu, rhea, 

 cassowary, and apteryx) are the nearest to the reptilian type, and 

 are all dull in color, with the exception of the head of the casso- 

 wary which may have a special explanation. The gulls and 

 albatrosses, which seem to stand next in order of development, 

 are brighter in plumage, but with very little trace of the sec- 

 ondary hues. Brilliant color is almost confined to the more re- 

 cent insessores. 



Among mammals, the early types of elephant, rhinoceros, hip- 

 popotamus, hog, etc., are quite without color, while the Carnivora 

 and the Euminantia, more characteristic of the present epoch, 

 have developed some warmer tints. The Mammalia, as a whole, 

 however, constitute the most recent of the great classes, and it 

 has not yet reached the stage of brilliant coloring. On the other 

 hand, the McUusca are extremely ancient, and among existing 

 Mollusks a large number display the most brilliant coloring in all 

 the secondary hues. 



The final result of the foregoing argument is that the gradual 

 development of organic color is a physiological necessity; that 

 brilliant coloration is a mark of the maturity of some organic 

 force-wave, in which the molecular rhythm has reached its maxi- 

 mum simplification ; and that the effect of insect selection in the 

 development of colored flowers is comparatively small. 



The very curious appearances of mimicry, which are often sup- 

 posed to be protective, but of which a large proportion seem lo 

 have no such function, may probably be attributed to sympathetic 

 communication of the vibratory motions, which must be passing 

 through the ether in all directions in the neighborhood of organic 

 life. 



An animal which spends its life in proximity to the brown bark 

 of trees will be under the influence of the molecular rhythm of 

 such bark, and may have its own molecular rhythm gradually 

 modified by sympathetic action, or it may entirely resist such 

 modification according to its fundamental molecular structure. 



The possibility of sympathetic modification of weaker vibrations 

 by a more energetic one, with which they are nearly synchronous, 

 is clearly suggested by the action of a sensitive flame, which, 

 while it is unaffected by vibrations which are palpably discordant, 

 shows itself sensitive to such as are nearly, but not quite, in uni- 

 son with it. An organism differs from a flame, as from a fixed 

 string or a tuning-fork, in the fact that it is constantly growing, 

 and the added molecules supply material which may be easily 

 amenable to modification. 



If the hypothesis here described should he found to explain 

 satisfactorily the phenomena of organic color, the corollaries to 

 be deduced from it will be far-reaching and of much interest, 

 and will apply to beauty of form as well as to brilliance of 

 color. 



The world in its early stages must have been sombre and un- 



