Septembeb 17, 1909] 



SCIENCE 



367 



cies are based ou previously known species 

 whose characters are, in part at least, recog- 

 nizably expressed in the diagnosis of the 

 genus. When they are not, such genera have 

 no basis and must necessarily be considered 

 ss non-existent. 



J. A. Allen 

 Amebican Museum of Xatubai Histobt 



the hypothesis of " presence and absence " 



IN itENDELIAN INHERITANCE 



In our last report we gave reasons for regard- 

 ing the rose-comb as a comb on which an addi- 

 tional element " roseness " has been superposed, 

 and we suggested that the allelomorphic pair 

 consists in the two states: presence of the factor 

 for rose (R) and absence of that factor (r). 

 The rose-comb is in reality a single comb modified 

 by the presence of a " rose " factor. The same 

 -considerations apply to the pea-comb, which is 

 fiingle comb plus a pea-factor.^ 



There are reasons for regarding man as a 

 •chimpanzee on which an additional element, 

 " manness," has been superposed. There you 

 iave man expressed or explained^ in terms of 

 Ms anthropoid ancestor. The characters of a 

 :frog are undoubtedly latent in the frog's tad- 

 pole. What is to hinder, therefore, expressing 

 or explaining the frog in terms of the tadpole 

 by saying the tadpole carries the characters 

 of the frog? The logic is sound in the state- 

 ment that the tadpole contains " frog factors " 

 or " frogness." The question is merely as to 

 the helpfulness of sound logic used that way. 



This seems like the method of reasoning 

 that, as somewhere remarked by Professor 

 William James, would enable Hegel and his 

 followers to successfully support the hypoth- 

 esis that men are always naked — under their 

 •clothes. 



I am not ailing with metaphysico-phobia. 

 Quite the contrary: upon occasion I enjoy 



'■ " Experimental Studies in the Physiology of 

 Heredity," by W. Bateson, Miss Saunders and 

 Tl. C. Punnett in " Reports to the Evolution Com- 

 mittee of the Royal Society," Report IV., 1908. 



' A few scholastics, more Abelard-like than the 

 generality in keenness of dialectic, point out that 

 there is an important distinction between " ex- 

 pressing " and " explaining " modern phenomena 

 -such as these. 



and can profit by a half-holiday in some cool, 

 shady deU of the land of metaphysics. I 

 recognize, nevertheless, that as a rule it is a 

 misfortune for metaphysics to get mixed with 

 objective science. I recognize further that 

 however unfortunate the mixture may be at 

 its worst when deliberately made, by far the 

 most unfortunate is such a mixture when 

 made all unconsciously on the part of the 

 mixers. 



The opening sentence of Huxley's essay 

 " Scientific and Pseudo-scientific Realism " is 

 this: 



Next to undue precipitation in anticipating the 

 results of pending investigations, the intellectual 

 sin which is commonest and most hurtful to those 

 who devote themselves to the increase of knowl- 

 edge is the omission to profit by the experience 

 of their predecessors recorded in the history of 

 science and philosophy. 



Were the distinguished fellow of the Royal 

 Society who wrote these lines living now, and 

 were he a member of that society's evolution 

 committee, he would, suiting action to word, 

 almost certainly have saved his fellow com- 

 mitteemen the labor of discovering that the 

 " allelomorphic pair consists in the two states, 

 presence of the factor for rose (R) and ab- 

 sence of that factor (r)," by referring them 

 to Hegel's " Logic," wherein the " divine prin- 

 ciple " of Negativitat is so fully and clearly 

 set forth that its applicability to such cases as 

 this becomes unmistakable. 



Difference implicit or in itself is a difference of 

 the essence, and includes both the positive and the 

 negative, and in this way: The positive is in the 

 identical connection with self in such a way as 

 not to be the negative, and the negative is the 

 difi'erence by itself so as not to be the positive. 

 Thus either is on its o^vn account, in proportion 

 as it is not the other.' 



The foundation of all determinateness is nega- 

 tion (as Spinoza says. Omnis determinatio est 

 negatio). Opinion, with its usual want of 

 thought, believes that specific things are positive 

 throughout, and retains them fast under the form 

 of being. Mere being however is not the end of 



' " The Doctrine of Essence," in " The Logic of 

 Hegel," translated by William Wallace. 



