PARTICULAR CASES 273 



be called a disease in the strict sense, and conditions of life are 

 conceivable in which it might even be advantageous. The innate 

 peculiarity may become exaggerated and complicated when 

 the eyes are forced to function in a way to which they are ill 

 adapted, and acquired " myopic " modifications may be super- 

 added to what was there by inheritance. Sometimes these 

 may even lead to an actually diseased condition. But though 

 the innate pecuUarity may be exaggerated and comphcated 

 by the addition of acquired modifications, there is no 

 evidence that these can be transmitted. What is trans- 

 mitted is a structural peculiarity which began as a germinal 

 variation, and that tliis is very liable to be transmitted one 

 does not require to go to Germany to see. It is said that 

 short-sightedness occurs, though rarely, among wild races. 



Bleeding. — A haemorrhagic tendency or liability to bleeding is 

 well known to be heritable, but it rarely finds expression except 

 in males. A case given by Klebs and cited by Sir William 

 Turner (1889) is instructive in showing how the tendency, 

 though transmitted through daughters (and therefore part 

 of their inheritance), finds expression only in the males, and in 

 illustrating first a diffusion, and then a waning of the peculiarity. 

 The black letters indicate the affected subjects or " bleeders." 



M F 



I I I I I I 



M F M F M M 



MF FMMMFMMF F MMMF MF MMFMM F 



J- _L _L _L _L ± I _L JL_ I 



II II' I II I II II I I I III II 



MF MF MFMF MF FMFMF FMF MF 



Cataract. — Mr. Bateson cites the following pedigrees of con- 

 genital cataract from Nettleship. The female at the top of 

 the first pedigree came of an affected family, but was probably 

 normal. Her son is said to have been certainly without cataract. 



18 



