664 THE POPULAR SCIENCE MONTHLY, 



record. I have given many such instances under the term of " inheri- 

 tance at corresponding ages." IsTo doubt the fact of variations being 

 sometimes inherited at an earlier age than that at which they first ap- 

 peared a form of inheritance which has been called by some natural- 

 ists " accelerated inheritance " is almost equally important, for, as 

 was shown in the first edition of the " Origin of Species," all the lead- 

 ing facts of embryology can be explained by these two forms of inher- 

 itance, combined with the fact of many variations arising at a some- 

 what late stage of life. A good instance of inheritance at a corre- 

 sponding age has lately been communicated to me by Mr. J. P. 

 Bishop, of Perry, Wyoming County, New York. The hair of a 

 gentleman of American birth (whose name I suppress) began to turn 

 gray when he was twenty years old, and in the course of four or five 

 years became perfectly white. He is now seventy-five years old, and 

 retains plenty of hair on his head. His wife had dark hair, which, at 

 the age of seventy, was only sprinkled with gray. They had four 

 children, all daughters, now grown to womanhood. The eldest daugh- 

 ter began to turn gray at about twenty, and her hair at thirty was 

 perfectly white. A second daughter began to be gray at the same 

 age, and her hair is noAV almost white. The two remaining daughters 

 have not inherited the peculiarity. Two of the maternal aunts of the 

 father of these children " began to turn gray at an early age, so that by 

 middle life their hair was white." Hence the gentleman in question 

 spoke of the change of color of his own hair as " a family peculiarity." 

 Mr. Bishop has also given me a case of inheritance of another kind, 

 namely, of a peculiarity which arose, as it appears, from an injury, 

 accompanied by a diseased state of the part. This latter fact seems to 

 be an important element in all such cases, as I have elsewhere endeav- 

 ored to show. A gentleman, when a boy, had the skin of both thumbs 

 badly cracked from exposure to cold, combined with some skin-disease. 

 His thumbs swelled greatly, and remained in this state for a long time. 

 When they healed they were misshapen, and the nails ever afterward 

 were singularly narrow, short, and thick. This gentleman had four 

 children, of whom the eldest, Sarah, had both her thumbs and nails 

 like her father's ; the third child, also a daughter, had one thumb simi- 

 larly deformed. The two other children, a boy and girl, were normal. 

 The daughter Sarah had four children, of whom the eldest and the 

 third, both daughters, had their two thumbs deformed ; the other two 

 children, a boy and girl, were normal. The great-grandchildren of 

 this gentleman were all normal. Mr. Bishop believes that the old gen- 

 tleman was correct in attributino: the state of his thumbs to cold aided 

 by skin-disease, as he positively asserted that his thumbs were not 

 originally misshapen, and there was no record of any previous inher- 

 ited tendency of tlie kind in his family. He had six brothers and sis- 

 ters, who lived to have families, some of them very large families, and 

 in none was there any trace of deformity in their thumbs. 



