The Laws of Heredity. 171 



between distant relatives out of the direct line of descent 

 between uncle and nephew, aunt and niece ; granduncle and 

 grandnephew, and cousins, even in the remoter degrees striking 

 resemblances of conformation, face, inclinations, passions, cha- 

 racter, deformity, and disease. 



But while the two forms of heredity, hitherto considered direct 

 heredity and atavism, are generally admitted, that now to be 

 discussed has been received with considerable distrust and doubt. 

 In the last century, Wollaston, 1 in The Religion of Nature Deli- 

 neated, after having shown that a child often more closely re- 

 sembles an uncle, an aunt, or a cousin, than it does either of its 

 parents, adds : ' Neither uncle, nor aunt, nor cousin have anything 

 to do with generation in this instance ; therefore the resemblance 

 does not proceed from the act of generation.' In this century 

 indirect heredity has been often denied, or doubted. Piorry, in 

 his Traite sur FHeredite des Maladies (1840), views it with sus- 

 picion. Baillarger, in the work already quoted, brings together one 

 hundred and forty-seven cases of mental disease traceable to 

 collateral heredity; but he judged it best to omit them from his 

 calculations, for the reason that ' heredity, under this indirect 

 form, although in most cases quite probable, still does not appear 

 to be unquestionable.' 



To explain these facts, which are so well established that it is 

 impossible to deny them, these authors have recourse to various 

 hypotheses. Some speak of the force of circumstances ; others 

 of accident ; others see in them nothing more than coincidence. 

 They all agree in finding here, in the last analysis, only the result 

 of chance. 



We have already seen, while considering Buckle's objection, 

 what is the value of such an explanation as this, how improbable 

 and inaccurate it really is. But the doctrine which insists on 

 collateral heredity has something better to offer than these negative 

 reasons. To show that it is correct, we need only remark that 

 indirect heredity is only a form of atavism a form which is rarer 

 and less easy of apprehension than direct atavism, but differing 

 from it only in appearance. The nephew resembles the uncle, the 



1 Quoted by Lucas. 



