MEMOIES OF THE NATIONAL ACADEMY OF SCIENCES. 143 



unnaturally, almost betrayed into the belief that the one is all-sufficient and the other inoperative. 

 But in the mind of one usually so candid and ever open to more evidence there naturally came a 

 reaction. The inheritance of functionally produced modifications, which, judging by the passage 

 quoted above concerning the views of these earlier inquirers, would seem to have been at onetime 

 denied, but which, as we have seen, was always to some extent recognized, came to be recognized 

 more and more, and deliberately included as a factor of importance. 



In his references to the works and opinions of other naturalists Mr. Speucer confines himself 

 almost exclusively to those of Mr. Darwin, who always opposed, and it must be confessed, with 

 less than his his usual candor and fairness, the views of Lamarck as to the influence of a change 

 in the environment upon organisms.* 



It seems singular that Mr. Spencer sh ould not be acquainted with the work of those who 

 have brought together certain facts bearing on the physical factors of evolution. f The principal 

 factors referred to by Mr. Spencer are use and disuse and the influence of light. In one place he 

 does in concrete language sum up these agencies as follows : 



The growth of a thing is effected hy the joint operation of certain forces on certain materials ; and when it 

 dwindles there is either a lack of some materials or the forces co-operate in a way different from that which pro- 

 duces growth. * * * That is to say, growth, variation, survival, death, if they are to be reduced to the forms in 

 which physical science can recognize them, must be expressed as effects ol agencies definitely conceived — mechanical 

 forces — light, heat, chemical affinity, etc. (pp. 39, 40). 



On page 70 Mr. Spencer remarks : 



But nevertheless, as we here see, natural selection could operate only under subjection. It could do no more 

 than take advantage of those structural changes which the medium and its contents initiated. 



Again, on page 73, Spencer suggests that natural selection, in order to act, must have had a 

 limited number of organisms upon which to operate.J As he remarks: 



Though natural selection must have become incre asingly active when once it had got a start, yet the differen- 

 tiating action of tbe medium never ceased to be a co-operator in the development of these first animals and plants. 



Finally, Mr. Spencer makes the following important admission : 



This general conclusion brings with it the thought that the phrases employed in discussing organic evolution, 

 though convenient and indeed needful, are liable to mislead us by veiling the actual agencies. That which really 

 goes on in every organism is the working together of component parts in ways conducing to the continuance of their 

 combined actions in presence of things and actions outside, some of which tend to subserve and others to destroy 

 tbe combination. The matters and forces in these two groups are the sole causes properly so called, ^he words 

 " natural selection" do not express a cause in the physical sense. They express a mode of co-operation among causes, 

 or rather, to speak strictly, they express an effect of this mode of co-operation (p. 40). 



Here we have frankly intimated what the Neolamarckian has for years insisted on, that the 

 phrase " natural selection " is not a vera causa, but rather expresses the results or effects of the 

 co operation of a number of factors in organic evolution. In the case of too many naturalists the 

 dogma or creed of natural selection has, it seems to us, tied their hands, obscured their vision, and 

 prevented their seeking by observation and experiment to discover, so far as human intelligence 

 can do so, the tangible, genuine, efficient factors of organic evolution. 



* It is surprising to read in Darwin's Life, by his son, the expressions showing his lack of appreciation of Lamarck 

 and his work; Darwin seems from the first to have been strongly prejudiced against Lamarck's views, and never to 

 have done them justice. 



In the Origin of Species (p. xiv, note) Darwin writes, as quoted by Spencer: "It is curious how largely my 

 grandfather, Dr. Erasmus Darwin, anticipated the views and erroneous grounds of opinion of Lamarck in his 'Zoo- 

 nomia' (vol. i, pp. 500-f>10), published in 1794" (p. 291. 



t In the writer's Introduction to the Standard Natural History, 1885, under the head of Evolution (pp. 1 and 

 lxii), he has endeavored to bring together references to the different authors who have insisted on views which are 

 in the line of those first suggested by Lamarck, a phase of evolution which he has called Neolamarckianism. The 

 authors to whom Mr. Spencer might have with good reason referred are, in Europe, Semper, Kolliker, Wagner, 

 Martins, Plateau, Wcismann, and Dohrn, and in this country Haldeman, Leidy, Wyman, Clark, Cope, Hyatt, Walsh, 

 Allen, W. H. Edwards, Dall, and the writer. 



tThis point is one which the writer has also made and published over twelve years ago in a communication to 

 The Nation, holding that it is an important objection to the theory of natural selection, the very nature of which 

 involves the existence of a world already stocked with life forms. What the theory of evolution should explain is 

 the origin of these first ordinal and class forms. Given even a scanty fauna, isolated members of different orders and 

 classes, and it is comparatively easy to account for the origin of the later more numerous descendants. 



