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THE POPULAR SCIENCE MONTHLY.— SUPPLEMENT. 



HEREDITARY TRAITS. 



IN Montaigne's well-known essay on the " Re- 

 semblance of Children to their Fathers," 

 the philosopher of Perigord remarks that " there 

 is a certain sort of crafty humility that springs 

 from presumption ; as this, for example, that we 

 confess our ignorance in many things, and are 

 so courteous as to acknowledge that there are in 

 works of Nature some qualities and conditions 

 that are imperceptible to us, and of which our 

 understanding cannot discern the means and 

 causes ; by which honest declaration we hope to 

 obtain that people shall also believe us of those 

 that we say we do understand. . . . We need not 

 trouble ourselves," he goes on, " to seek out 

 miracles and strange difficulties ; methinks there 

 are such incomprehensible wonders among the 

 things that we ordinarily see as surpass all diffi- 

 culties of miracles." He applies these remarks 

 to inherited peculiarities of feature, figure, char- 

 acter, constitution, habits, and so forth. And 

 certainly few of the phenomena of Nature are 

 more wonderful than these, in the sense of being 

 less obviously referable to any cause which seems 

 competent to produce them. Many of those 

 natural phenomena which arc regarded as most 

 striking are in this respect not to be compared 

 with the known phenomena of heredity. The 

 motions of the planets can all be referred to 

 regular laws ; chemical changes are systematic, 

 and their sequence at least is understood ; the 

 phenomena of heat, light, and electricity, are 

 gradually finding interpretation. It is true that 

 all these phenomena become in a sense as mira- 

 cles when we endeavor to ascertain their real 

 cause. In their case we can ascertain the " how," 

 but in no sense the " why." Gravity is a mys- 

 tery of mysteries to the astronomer, and has 

 almost compelled us to believe in that " action at 

 a distance " which Newton asserted to be unim- 

 aginable by any one with a competent power of 

 reasoning about things philosophical. The ulti- 

 mate cause of chemical changes is as great a 

 mystery now as it was when the four elements 

 were believed in. And the nature of the ether 

 itself in which the undulations of heat, light, and 

 electricity, are transmitted, is utterly mysterious 

 even to those students of science who have been 

 most successful in determining the laws accord- 

 ing to which those undulations proceed. But the 

 phenomena themselves being at once referable 

 (in our own time at least) to law, have no longer 



the mysterious and in a sense miraculous charac- 

 ter recognized in them before the laws of motion, 

 of chemical affinity, of light and heat, and elec- 

 tricity, had been ascertained. It is quite other- 

 wise with the phenomena of heredity. We know 

 nothing even of the proximate cause of any single 

 phenomenon ; far less of that ultimate cause in 

 which all these phenomena had their origin. The 

 inheritance of a trait of bodily figure, character, 

 or manner, is a mystery as great as that other and 

 cognate mystery, the appearance of some seem- 

 ingly sudden variation in a race which has for 

 many generations presented an apparently un- 

 varying succession of attributes, bodily, physical, 

 or mental. 



It need hardly be said that this would not be 

 the place for the discussion of the problems of 

 heredity and variation, even if in the present 

 position of science we could hope for any profit- 

 able result from the investigation of either sub- 

 ject. But some of the curious facts which have 

 been noted by various students of heredity will, 

 we think, be found interesting ; and though not 

 suggesting in the remotest degree any solution 

 of the real difficulties of the subject, they may 

 afford some indication of the laws according to 

 which parental traits are inherited, or seemingly 

 sudden variations introduced. 



The commonest, and therefore the least in- 

 teresting, though perhaps the most instructive of 

 the phenomena of heredity, are those affecting 

 the features and the outward configuration of the 

 body. These have been recognized in all ages, 

 and among all nations. A portion of the Jewish 

 system of legislature was based on a recognition 

 of the law that children inherit the bodily quali- 

 ties of the parents. The Greeks noted the same 

 fact. Among the Spartans, indeed, a system of 

 selection from among new-born children pre- 

 vailed, which, though probably intended only to 

 eliminate the weaker individuals, corresponded 

 closely to what would be done by a nation having 

 full belief in the efficacy of both natural and ar- 

 tificial selection, and not troubled with any strong 

 scruples as to the method of applying their doc- 

 trines on such matters. Among the Romans we 

 find certain families described by their physical 

 characteristics, as the Nasoncs or Big-nosed, the 

 Zabconci or Thick-lipped, the Capitones or Big- 

 headed, the Buccones or Swollen-cheeked. In 

 more recent times similar traits have been recog- 



