NATURE 



257 



THURSDAY, JULY 21, 1881 



INHERITANCE 



THE tendency in any new character or modification to 

 reappear in the offspring at the same age at which 

 it first appeared in the parents or in one of the parents, is 

 of so much importance in reference to the diversified 

 characters proper to the larvte of many animals at succes- 

 sive ages, that almost any fresh instance is worth putting 

 on record. I have given many such instances under the 

 term of "inheritance at corresponding ages." No doubt 

 the fact of variations being sometimes inherited at an 

 earlier age than that at vhich they first appeared— a 

 form of inheritance which has been called by some 

 naturalists " accelerated inheritance " — is almost equally 

 important, for, as was shov\ n in the first edition of the 

 "Origin of Species," all the leading facts of embryology 

 can be explained by these two forms of inheritance, com- 

 bined with the fact of many variations arising at a some- 

 what late stage of life. A good instance of inheritance at 

 a corresponding age has lately been communicated to me 

 by Mr. J. P. Bishop of Perry, Wyoming, N.Y., United 

 States : — The hair of a gentleman of American birth 

 (whose name I suppress) began to turn grey 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 grey. They had four children, all daughters, now 

 grown to womanhood. The eldest daughter began to 

 turn grey at about twenty, and her hair at thirty was per- 

 fectly white. A second daughter began to be grey at the 

 same age, and her hair is now 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 grey at an early age, so that by middle 

 life their hair was white." Hence the gentleman in ques- 

 tion spoke of the change of colour 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 en- 

 deavoured to show. A gentleman, when a boy, had the 

 skin of both thumbs badly cracked from e.xposure 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 after- 

 wards 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 similarly defoniicd. 

 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 de- 

 formed ; 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 gentleman 

 was correct in attributing the state of his thumbs to cold 

 aided by skin disease, as he positively asserted that his 

 Vol. .\xiv. — No. 612 



thumbs were not originally misshapen, and there was no 

 record of any previous inherited tendency of the kind in 

 his family. He had six brothers and sisters, who lived to 

 have families, some of them very large families, and in 

 none was there any trace of deformity in their thumbs. 



Several more or less closely analogous cases have been 

 recorded ; but until within a recent period every one natu- 

 rally felt much doubt whether the effects of a mutilation 

 or injury were ever really inherited, as accidental coinci- 

 dences would almost certainly occasionally occur. The 

 subject, however, now wears a totally different aspect, 

 since Dr. Brown-Sdquard's famous experiments proving 

 that guinea-pigs of the next generation were affected by 

 operations on certain nerves. Mr. Eugene Dupuy of San 

 Francisco, California, has likewise found, as he informs 

 me, that with these animals " lesions of nerve-trunks 

 are almost invariably transmitted." For instance, " the 

 effects of sections of the cervical sympathetic on the 

 eyes are reproduced in the young, also epilepsy (as 

 described by my eminent friend and master, Dr. Brown- 

 Sdquard) when induced by lesions of the sciatic nerve." 

 Mr. Dupuy has communicated to me a still more remark- 

 able case of the transmitted effects on the brain from an 

 injury to a nerve ; but I do not feel at liberty to give 

 this case, as Mr Dupuy intends to pursue his researches, 

 and will, as I hope, publish the results. 



July 13 Charles Darwin 



VOLCANOES 



Volcanoes: what they are, and what they Teach. By 



John W. Judd, F.R. S., Professor of Geology in the 



Royal School of Mines. (London : C. Kegan Paul 



and Co., 1S81.) 



ONE of the fathers of vulcanology in this country was 

 the late Mr. Poulett Scrope, in whose well-known 

 treatise on Volcanoes, the subject of their cause and effect 

 was for the first time discussed from a thoroughly philo- 

 sophical standpoint. A great traveller and investigator 

 himself, he strove to imbue younger geologists with his 

 spirit, and when he became too old and infirm to undertake 

 travel and research in distant countries, he directed some 

 chosen disciples to prosecute his favourite lines of thought. 

 Prof Judd was one of these, and upon him has assuredly 

 fallen the mantle, and a portion of the spirit of his master. 

 His able papers on the study of volcanoes, contributed to 

 the Geological Magazine, are well known to every vulcan- 

 ologist. He has travelled much ; he makes good use of 

 both pen and pencil, and he is an accurate observer. We 

 are glad that he has condensed his reading and research 

 into a work, which becomes so widely distributed, both at 

 home and abroad, as the volumes of the International 

 Scientific Series invariably do. 



Before entering more minutely into a discussion of the 

 work, we would venture to say that among its few defects, 

 that which strikes us most prominently is an insufficiency 

 of logical sequence and method. The facts are multi- 

 tudinous ; carefully selected, but not carefully arranged. 

 They require to be grouped ; to be classified, and each 

 set of facts to be set in apposition to the generalisation 

 which they tend to prove. It is indeed a useful mental 

 discipline for the reader to do this for himself, but unless 

 he starts with some knowledge of the subject, and as the 



