INHERITANCE OF MENTAL DEFECTS AND DISEASE 65 
produce more serious degeneracy and terminate in the idiocy or 
imbecility of those who form the last link in the chain of hered- 
itary transmission.” 
Dr. Moreau, a prominent member of the same school, tells 
us that “‘it is not in the identity of functions, or of organic or 
intellectual facts that we must seek the application of the law of 
heredity, but at the very fountain head of the organism, in its 
inmost constitution. A family whose head has died insane or 
epileptic does not of necessity consist of lunatics and epileptics, 
but the children may be idiotic, paralytic, or scrofulous. What 
the parents transmit to the children is not insanity, but a vicious 
constitution which will manifest itself under various forms in 
epilepsy, hysteria, scrofula, rickets, etc. This is what is to be 
understood by hereditary transmission.” 
The same idea is emphasized by Féré in La Famille Neuro- 
pathique. ‘Le plus souvent, la maladie qui se transmet se trans- 
forme; c’est ainsi qu’on voit succéder la manie, la mélancolie, 
Vimbécillité, Vidiotie.” The lack of fidelity which characterizes 
the transmission of defect is regarded as a result of the “‘dissolu- 
tion of heredity’ occasioned by a lack of developmental energy 
(defaut d’energie émbryogenique). “La dégredation de la puis- 
sance émbryogenique, démontrée par la fréquence de malfor- 
mations variées, et en fin de compte par la stérilité dans les races 
dégénérées permet de comprendre 4 la fois Ihérédité morbide 
dissemblable, et l’hérédité morbide collaterale.” But, as Féré 
hastens to add, the sequences of degenerative changes do not 
follow without rhyme or reason. There is a more or less definite 
grouping of symptoms constituting a family of related defects. 
“La dégénérescence a ses lois comme ]’évolution normale; quelle 
que soit sa cause, elle se manifeste sous un petit nombre de formes 
communes.” 
If degeneration is due to a general defect of developmental 
energy or the presence of factors which exercise an injurious 
influence upon the evolution of the embryo, its protean manifes- 
tations need not surprise us. One of the most conspicuous fea- 
tures of the results of experimentation upon the effects of external 
