74 



SCIENCE. 



[Vol. X. No. 236 



of the successive changes which tal:e place in the bird during this 

 process, — changes in color, during which the more conspicuous 

 features of protective coloring are lost ; changes in habit, in which 

 are seen the undoing or relaxing of those features which indicate 

 constant vigilance, from carrying itself in a semi-erect attitude, 

 perching on the tallest trees, covering up the eggs carefully with 

 leaves when off the nest, etc., to moving in a horizontal attitude, 

 perching near the ground, covering the eggs but slightly or care- 

 lessly, etc., and losing that wildness which characterizes the bird 

 in its wild state. At the breeding-season, however, the females be- 

 came wild again, but this was a feature too deeply implanted to 

 show modification in the time allotted to Mr. Caton's experiment. 

 The same writer has also observed in the Hawaiian Islands the 

 effects of reversion to a wild state, of different kinds of domestic 

 animals which have from time to time been carried there. Among 

 other animals, he was fortunate enough to observe the undoing 

 stages in the domestic turkey, and the assumption of those features 

 which characterize the wild bird. 



A great many facts illustrating the plainest features of natural 

 selection, protective coloring, mimicry, etc., have been recorded in 

 our journals from time to time. A brief allusion may be made to 

 a few of these. . . . Dr. R. E. C. Stearns has made some interest- 

 ing notes on protective coloring in Phrynosoma. Having collected 

 these horned lizards (or toads, as they are commonly called) in 

 central California, he has noticed, that, if the ground region they 

 frequent is yellowish, the lizards are, without exception, of that 

 color ; if ashen gray, then that color is simulated ; and this, with- 

 out exception. 



An unquestionable fact has been finally established by recent 

 methods of observation on the habits of insects and other animals, 

 and that is, that individuals of the same species vary in intelligence ; 

 that they are not automata ; that they are not impelled by a blind 

 instinct to perform certain acts with unerring accuracy, but, on the 

 contrary, that they vary, and often greatly vary, in their ability to 

 provide for their young, in their skill to secure sufficient food, in 

 their wit to avoid danger : in other words, they make blunders and 

 mistakes, and involve their progeny and even their colony in ruin. 

 This individual variation in intelligence is brought out very clearly 

 by a patient series of observations made by Drs. G. W. and E. G. 

 Peckham on the special senses of wasps. They not only repeated 

 many of the experiments of Sir John Lubbock, but many new and 

 ingenious experiments were devised. Their studies were for the 

 purpose of investigating the mental power, sense of hearing, color, 

 direction, memory, emotion, power of communication, general in- 

 telligence, etc. An interesting result of their painstaking work was 

 the determination of individual differences as to the faculty of mem- 

 ory and power of distinguishing color and direction. This kind of 

 study of the habits of insects has brought to light features of the 

 most surprising character. The remarkable studies of Sir John 

 Lubbock, Dr. Moggridge, and others in Europe, have been paralleled 

 in this country not only by the observations above quoted, but 

 notably by the labors of Rev. H. C. McCook in his studies of the 

 American ants and spiders. 



Dr. Thomas Meehan describes a hornet that was gifted with 

 great intelligence. He saw this insect struggling with a large locust 

 in unsuccessful attempts to fly away with it. After several fruitless 

 efforts to fly up from the ground with his victim, he finally dragged 

 it fully thirty feet to a tree, to the top of which he laboriously as- 

 cended, still clinging to his burden, and, having attained this ele- 

 vated position, he flew off in a horizontal direction with the locust. 

 Dr. Meehan truly says, " There was more than instinct in this act : 

 there was reasoning on certain facts, and judgment accordingly, 

 and the insect's judgment had proved correct." 



The delicate balance of conditions between organisms, whether 

 it be between individuals of the same species or between widely 

 separated groups, is an important feature in the question of sur- 

 vival. Prof. S. A. Forbes, in a thoughtful study of certain species 

 of Entomostraca in Lake Michigan and the surrounding waters, 

 calls attention to the important part played by these minute crus- 



taceans, showing how they furnish almost the entire food for young 

 fishes, larger crustaceans, and even insect larvae. He writes, " Mol- 

 lusca, one would say, could afford to be indifferent to them, since 

 they neither eat them nor are eaten by them, nor seem to come in 

 contact with them anywhere, through any of their habits or neces- 

 sities. But for this very reason these two classes afford an excel- 

 lent illustration of the stringent system of re-actions by which an 

 assemblage of even the most diverse and seemingly independent 

 organisms is held together. ... If there were no Entomostraca 

 for young fishes to eat, there would be very few fishes indeed 

 to feed upon Mollusca, and that class would flourish almost with- 

 out restraint ; while, on the other hand, if there were no Mollusca 

 for the support of adult fishes, Entomostraca would be relieved 

 from a considerable part of the drain upon their numbers, and 

 would multiply accordingly." He is much struck with the fact that 

 in the larger bodies of water the species of Entomostraca show an 

 inferior development in numbers, size, and robustness, and in re- 

 productive power. Their smaller number and size are doubtless 

 due to the relative scarcity of food. 



The effect of mechanical strains as producing morphological 

 effects has been treated in a masterly way by Dr. John A. 

 Ryder. . . . Prof. A. Hyatt, in an exhaustive study, shows, among 

 other things, the effect of gravitation as accounting for the form of 

 the moUusk-shell, citing examples from all the classes, and even 

 drawing examples from other sub-kingdoms, to support his views. 



Prof. E. D. Cope, in a memoir on archsesthetism, considers the 

 hypothesis of use and effort, the office of consciousness, etc. He 

 attempts to show that consciousness is primitive, and a cause of 

 evolution. He sustains his thesis by a series of arguments, which, 

 if not beyond my grasp, would be too extensive to present here. I 

 can only repeat the regret I expressed in the Buffalo address ; 

 namely, that neither Professor Cope nor Professor Hyatt have yet 

 been induced to present to the public an illustrated and simple out- 

 line of their theories. Such a demonstration, I am sure, would be 

 acceptable not only to the public, but to many scientific students 

 as well. While these two eminent naturalists believe fully in the 

 derivative theory, they insist that Darwin's theory is inadequate to 

 explain many of the phenomena and facts which they encounter in 

 their studies. Darwin has distinctly said in his first edition of 

 the ' Origin of Species,' " I am convinced that natural selection 

 has been the main but not the exclusive means of modification ; " 

 and in his sixth edition of the same work, in quoting these words, 

 he laments that he is stifl misunderstood on this point. The 

 theory of acceleration and retardation of these authors is, if I un- 

 derstand it rightly, a very plain case of natural selection. It was 

 inevitable that those individuals that matured the quickest were 

 better prepared to defend themselves, were quicker in the field, 

 were able to give their offspring an earlier start in the season, were 

 in every way more fitted to survive, than those which matured 

 later. It is assumed that this is a law, when, to my mind, it seems 

 the simplest result of natural selection. Instead of overriding it, 

 it is only a conspicuous result and proof of it. 



A parallel case may be seen in the increase in size of the brain 

 in the vertebrates, and conspicuously in the higher vertebrates, 

 since their first appearance in geological history. The individual 

 brain clearly varies in size ; and it does not require a great effort 

 to perceive how, in the long-run, the greater brain survives in the 

 complex struggle for existence. Assosiated with the greater de- 

 velopment, parts that were freely used for locomotion before, now 

 are compelled to perform additional service, and through the law 

 of use and effort, which all admit as an important factor, organs 

 are modified in structure, the anterior portion of the body assumes 

 a new aspect ; and it was on the character of these parts and 

 aspects that Professor Dana was led to formulate his compre- 

 hensive and ingenious principle of cephalization. It is a result, 

 and not a cause. And so I believe, though witn great deference to 

 Cope and Hyatt, that the laws of acceleration and retardation, 

 exact parallelisms, inexact parallelisms and still more inexact par- 

 allelisms, and many other laws and theories advanced by these 

 gentlemen, are not causes, but effects, to be explained by the doc- 

 trine of natural selection and ' survival of the fittest.' 



The connecting links and intermediate forms which the sceptical 



