26 



on the child may seem abolished, it is never annihilated," 

 and thus "the law of equality of action is as far as possible 

 realised." To sum up a child, in the case of direct 

 heredity, derives its qualities from both parents, but there is 

 always a preponderance of one of them. 



(2) The preponderance may be either direct or diagonal 

 viz., direct when the son resembles the father, and the 

 daughter the mother ; diagonal when the son resembles the 

 mother, and the daughter the father. The law of diagonal 

 heredity has comparatively few exceptions, and may be 

 explained by a cycle of heredity, thus : by examining 

 several generations, it is found to pass from the grandfather 

 to the mother, and from the mother to the son ; or from 

 the grandmother to the father, and from the father to the 

 daughter, then back again from whence it started. Cross or 

 diagonal heredity is still more common when one of the 

 parents presents any anomaly or deformity, thus : organic 

 imperfections (as curved spinej lameness, rickets, sex-digitism, 

 deaf-muteness, mycrophthalmy, etc.) pass from father to 

 daughter, and from mother to son. Gall cites a case of twins 

 of opposite sexes the boy like the mother, very stupid ; the 

 girl like the father, very intelligent. 



(3) The preponderance of one parent is sometimes shown 

 in the children of the same sex, but instances of this kind 

 are not so numerous as in cross heredity. Edward Lambert, 

 "the Human Porcupine," transmitted his peculiarity only 

 to the males of his family. Daltonism, or colour-blindness, 

 is generally more frequent in men than in women, yet it has 

 been transmitted through five generations, to twelve persons, 

 all women ! " Constitution, temperament, fecundity, lon- 

 gevity, idiosyncrasies, and anomalies of every kind, pass as 

 often from father to son as from mother to daughter." 1 



1 Ribot. 



