HEREDITY IN PHYSIOLOGY, IN MEDICINE, ETC. 343 
His father was a lawyer, and an insatiate reader of the 
“‘Contrat social.” Peter the Cruel, King of Castile, was the 
son of Alphonso XI., who lived on bad terms with his wife. 
Scandalous scenes of anger, jealousy, and violence, contin- 
ually disturbed the royal household, and the issue of the in- 
tercourse of the married pair was Peter the Cruel, a monster 
of physical and moral ugliness. History shows us Raphael’s 
parents, both devoted to the art of painting. The wife, a 
real Madonna, delighted in pious and graceful subjects. The 
father, a vigorous dauber, preferred energy for his share. 
Ribot, in the remarkable work which he has just devoted 
to heredity, examines the laws of that mysterious influence 
which he judges to be a kind of habit, or perpetual memory. 
These laws are little else than the ascertainment of the usual 
directions in which the hereditary impulse acts. Sometimes 
transmission passes from the father to the daughter, from 
the mother to the son; sometimes the child takes from both 
its parents. Again, it often occurs that the child, instead of 
being like its immediate parents, resembles one of its grand- 
parents or some yet more remote ancestor, or some distant 
member of a collateral branch of the family. This is what 
is called atavism, or reversed heredity." The latter fact 
was well known to the ancients. Montaigne expresses his 
wonder at it. ‘“ What a prodigy is it,” he says, “that the 
drop of seed from which. we spring bears in itself not 
1The singular phenomenon of alternating generations has been com- 
pared with atavism. In 1818, Chamisso, in studying the b¢phora or salpas, 
discovered that these creatures are alternately single or grouped. In the 
first generation the biphora are found as chains, produced by gemmation ; 
in the second they are single, produced by spores; in the third we find 
chains of biphora again, so that the son is never like its father, and 
always like its grandfather. The researches of Saars and Steenstrup 
have brought the fact to light that in some other creatures the cycle goes 
through three generations, and that the likeness, instead of being one be- 
tween the grandfather and grandson, is one between the great-grand- 
father and the great-grandson. 
