XII] Human Albinism 227 



records of congenital albinos acqiiirlnci^ pigmentation more 

 or less complete. Lastly, albinism in man differs greatly 

 from that in other forms in the fact that it is very often 

 associated with disease, especially of the nervous system. 

 Even nystagmus, the oscillating movement of the eyes so 

 generally associated with human albinism, is not, so far as 

 I know, met with in the pink-eyed rabbits, guinea-pigs, 

 rats or mice. In the cat however somethinor more like 

 human albinism is to be seen, for in that animal we find 

 the association of certain types of albinism with deafness, 

 and in it also several degrees of pigmentation in the iris 

 occur. Careful pedigrees of crosses with albino cats might 

 help to a solution of this problem. But in studying the 

 subject of human albinism and also that of retinitis pigmen- 

 tosa one meets not infrequently features indicative of a 

 widespread and multiform degeneration in the affected family 

 not at all resembling the simple course of Mendelian in- 

 heritance where natural variations are concerned. It is at 

 least doubtful whether there may not be some distinction 

 between albinism thus appearing and that less definitely 

 associated with disease. 



An interesting observation is recorded by Stedman 

 {Stirinaui, 1806, 11. p. 260) to the effect that an albino 

 negress married to a European had children all mulattos. 

 Hence we may infer that the factor determining the black- 

 ness of the negro may be carried by the albino. The great 

 Irequency of albinos among several coloured races of men 

 has often been remarked on by anthropologists. 



A rare condition known as Alkaptoiiuria in which the 

 urine is red from the presence of the substance alkapton 

 must surely be a recessive. The facts published by Garrod* 

 make it likely that the disease follows recessive lines, for 

 of 17 families in which cases have been seen, 8 were 

 offspring of first cousins. On the other hand Garrod gives 



* Garrod, A. E., Lancet, 1902, Dec. 13, and Arch. f. Gcs. Physiolo^^ie, 

 Bd. 97, 1903, p. 410. The inheritance of cystinuria would be equally 

 interesting ; see Garrod, ibid, and Abderhalden, Ztsch. f. Physiol. Chcmic, 

 1903, xxxvni. p. 557. For a valuable discussion of the evidence see also 

 Garrod (127). Since that paper was published he has called my attention 

 to a fresh tamily discovered by Fromher/, Imiug. Diss., Strassburg, 1908, 

 containing 3 alkaptoniirics and 8 or 9 normals. 



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