3 i8 THE POPULAR SCIENCE MONTHLY. 



the light, or partly sanguine group, to active inflammations, a potent 

 factor in causing this deficient size of the chest is inflammation, 

 mainly pleurisy and pneumonia, and, as a not uncommon result, a 

 collapse of one, or both, of the chest-walls. This theory is the only 

 one that offers a reasonable explanation of a very remarkable sta- 

 tistical result. The increased ratio in both groups, but notably 

 in the liffht, of defects or deformities of the feet rather than of 

 the hands, while having no relation to the difference of temper- 

 ament, shows the careful way in which Nature protects the natural 

 weapons of human beings the hands. It confirms, in a broad way, 

 what has probably been noticed by the observant reader, that de- 

 formities of the lower are more frequent than those of the upper 

 extremities. 



These few figures, taken from Dr. Baxter's vast collection of sta- 

 tistics, if not demonstrating anything positively, have at least the 

 merit of not proving too much a common fault of figures, if we are 

 to believe the anti-statisticians. They are important, however, in 

 showing the direction in which the study of temperaments may be 

 pushed in order to give practical results. Social reformers, so called, 

 human-science men, and less respectable students under various names, 

 have used temperaments as their physiological basis for widely difler- 

 ent theories. To one who is content with marriage as established by 

 law, society, and religion, it is a suspicious circumstance that this is 

 the social relation that has sustained the most determined assaults. 

 The physiological attacks have been made in the interests of mar- 

 riage-reform, " natural marriage," and of no marriage at all. While 

 there is very strong evidence showing that intermarriage between re- 

 lations tends to the deterioration of the offspring, there are hardly 

 any facts showing that the matrimonial union of healthy persons of 

 like temperaments has the same effect. It is true that social theorists 

 assert the contrary, but they do so without considering that the inter- 

 marriage of kin, from which they draw their chief arguments, is 

 surrounded by conditions that cannot exist in the intermarriage of 

 like temperaments. That there are deep-lying physiological reasons 

 against the union of relations, we need go no further than the oft- 

 quoted fact of the sure impairment of the stock of domestic animals 

 from inbreeding, to establish. Whatever the source of this gradual 

 impairment may be, it is wanting in the marriage of those who are 

 allied only by similarity of temperament. In the absence of condi- 

 tions that are necessary to render the arguments drawn from analogy 

 valid, the advocates of the theory of physiological incompatibility'are 

 obliged to fall back upon facts having a direct bearing, and they have 

 in this field, as yet, reaped no harvest. There is, however, in the hu- 

 man family a sort of natural selection existing, that renders a marriage 

 between parties of like temperament not an ordinary occurrence. 

 Both Dr. Ryan and Mr. Walker, in their w r orks on marriage, refer to 



