910 



SCIENCE. 



[N. S. Vol. XI. No. 284. 



examples of hypercriticisin, but there are other 

 objections which are distinctly so. (a) I say, 

 the olfactive nerve is specialized for the percep- 

 tion of odors, he objects that the terminations 

 alone are thus specialized. This may be true, 

 but is not the termination also included in my 

 general statement ? (6) I say a muscle is an 

 arrangement for changing nerve-force into me- 

 chanical power. He apparently objects, but 

 why he does not say and I cannot imagine. 

 The statement is certainly true, (c) He re- 

 proaches me for certain important omissions, 

 e. g., the mesodermal origin of metameres. Surely 

 this objection implies an attitude of mind 

 wholly inconsistent with the writing of an out- 

 line. 



3. A few of his criticisms are pure mistakes 

 or else misunderstandings of my meaning. For 

 example (a) he quotes me as saying that ' no 

 voice is known below hexapod insects ' and 

 cites the stridulation of spiders and crustaceans. 

 I did not say so. I said ' below this department,' 

 i. e., arthropods. (6) I state that homologies are 

 not distinctly traceable beyond the limits of a 

 Phylum. The cases of homologies beyond these 

 limits which he mentions are not certainly ex- 

 amples of homology but of analogy, not evi- 

 dences of common origin but of adaptive modi- 

 fication. But in any case it must be remem- 

 bered that I was tracing homology only in the 

 clearest cases and as an argument for Evolu- 

 tion, (c) He says I omit all mention of 

 branchife in Asterias although I mention them 

 in Echinus. Is he sure that there are any such 

 in Asterias ? Perhaps they are among the new- 

 est things which he accuses me of neglecting. 



4. Some of the objections he makes concern 

 points still in doubt, e. g. , the function of the 

 pedicillarise in echinoids. The function I gave, 

 viz, that of carrying food to the mouth, is still 

 held and is not inconsistent with that which he 

 probablj^ had in mind, viz, the cleansing of the 

 body. 



5. Besides these there are, I frankly ac- 

 knowledge, some real mistakes. It would be 

 strange if there were not. For pointing out 

 these I most heartily thank him. I will profit 

 by his criticisms. 



But I fear I weary the reader with personal 

 mattei'S which are of little importance. It is 



with real pleasure therefore that I hasten on 

 to take up the last point, which is one of 

 great interest in the general field of scientific 

 thought. 



6. The worst fault which Professor Kingsley 

 finds in my book is ' the recognition of a vital 

 force.'' Now this really amuses me. Surely 

 Professor Kingsley must be ignorant of the 

 early history of discussions on this sub- 

 ject or he would be aware that I was 

 myself among the earliest enforcers of the 

 doctrine of ' the correlation of vital with 

 physical and chemical forces and the conser- 

 vation of energy in the phenomena of living 

 things.' I even suffered somewhat from the 

 odium theologicum on that account. That my 

 contributions to the discussion were not unim- 

 portant see the references given below.* The 

 position I held then is so universally acknowl- 

 edged now that the history of the discussion 

 has lost something of its interest to the present 

 generation. But some would go farther. In 

 the revulsion against the old idea of vitality as 

 an independent supra natural force unrelated 

 to the other forces of nature the scientific 

 mind swung too far in the contrary direction, 

 and it become the fashion for scientific men to 

 ridicule even the use of the term vital force as 

 the useless remnant of an old superstition and 

 indicating a wholly unscientific attitude of 

 mind ; and thus gradually arose an odium scien- 

 tificum forbidding the use of the term on pain 

 of being thought unscientific. And yet the 

 same men who repudiate life as a force talk 

 serenely of gravity as a force or chemical af- 

 finitj' as a force, or the force of attraction or 

 of inertia, wholly unconscious of any incon- 

 sistency in their position. The fact is, all of 

 these stand on the same footing. They are 

 none of them forces in the old sense of inde- 

 pendent entities — they are all of them forces in 

 the sense of different forms of the one universal 

 energy, they are all derivable from and con- 

 vertible into one another. They are all different 

 forms of energy, determined by different condi- 



-^Am. Jour. Sci., Vol. 28, p. 305, Nov., 1859 ; Phil. 

 Mag., Vol. 19, p. 133 and 243, 1860 ; Pop. Sti. 

 Monthly for Dec, 1873 ; Carpenter's Physiology, 7th ed., 

 p. 7; McGee, Fifty Years of Am. Soi. ; Atlantic 3Ionthly 

 Sept., 1898. 



