Full text: papers communicated to the first International Eugenics Congress held at the University of London, July 24th to 30th, 1912

V. G. Ruggeri.Biology and Eugenics.41 
if we consider that this can also happen amongst distantly related cousins, 
who are naturally ignorant of their relationship. 
The recessive character of albinism and obedience to the Mendelian law 
seem, then, well established, in spite of the mathematical criticisms of 
Pearson, which we pass over, as the same Davenports have replied to them. 
Without wishing to enter into particulars special mention should, 
however, be made of a family of mulattos of Louisiana with partial 
hereditary albinism, which has been studied in Italy by Frassetto and Levi(i). 
The genealogical tree shows various generations, each of which presented 
one albino parent. But one of these generations is specially interesting for 
the large number of children born to one couple, viz., 15, of whom eight 
were albinos: the percentage of albinism is very nearly 50 per cent., as was 
foreseen from the theory, admitting that the normally pigmented parent had 
had the character of albinism as a recessive, according to the formula 
(dr x r r), in which d = dominant, r = reoessive or remissive. In the next 
generation the descendants are still few (and also their number varies 
according to the two authorities), and their behaviour would make it 
difficult—if it were not too soon to draw conclusions—to deny that they 
confirm the Mendelian law. 
On the other hand, if the normally pigmented parent does not possess the 
character of albinism as a recessive the behaviour is different—i.e., in the 
first generation none of the children ought to show evident albinism. The 
case of Farabee(2) isi much to the point. An albino negro wedded to a negress 
had three normally pigmented children. But the latent albinism showed 
itself in the second generation exactly as we have seen for the albino mice. 
Since one of the three sons had 15 children of two negresses, of whom four 
were albinos, which corresponds precisely to the division of the determinants, 
the isolated recessive character remaining and hence being evident in the four 
children. This behaviour shows that even in the second generation the 
character of albinism was recessive in only one of the two parents ; otherwise 
the proportion would have been 50 per cent, as in the case Frassetto-Levi. 
Clearly families with few children afford much less demonstration. 
As a general rule when a generation is passed over, as in the case referred 
to, it may be said that the character is recessive. It would seem that red 
hair is in a similar case, since Frédéric refers to a southern German with red 
hair, who had two sisters with brown hair, both the parents also had brown 
hair, while one grandmother had red hair. 
Nevertheless, Frédéric, with much caution, leaves the question of 
Mendelism in suspense, whether as regards red hair or albinism, although 
(1) E. Levi, Albinismo parziale eredo-famigliare in Negri della Luisiana. Arch, per 
l’Antrop. e l’Etnol XXXIX. (1909), fase. 1 ; F. Frassetto, Casi di albinismo parziale eredi- 
tario nella famiglia Anderson della Luisiana. Atti Soc. Rom. di Antrop. XV. (1910), fasc. 2. 
(2) W. C. Farabee, Notes on a Negro Albinism. Science, New Series, XVII. (iqcu). Jan.-June.
        

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