October 5, 1900.] 



SCIENCE. 



527 



resulted in deaf oflfspring ; and the proportion 

 of deaf children born therefrom is 1.2 per cent. 

 The actual percentage of marriages resulting in 

 deaf offspring, and the number of deaf chil- 

 dren born therefrom, when neither of the 

 parents has deaf relatives, may be even smaller 

 than these figures indicate ; for in some cases 

 the statement that neither parent had deaf 

 relatives is not well authenticated, and in all of 

 them there is the possibility that there may 

 have been deaf relatives who were unknown to 

 the person who filled out the record-blanks. 

 Professor Fay is led to believe, from the study 

 of the records, that the probability of deaf 

 children, where neither parent had deaf rela- 

 tives, is very slight, perhaps no greater than in 

 ordinary marriages. 



The marriages of the deaf most liable to re- 

 sult in deaf offspring are those in which the 

 partners are related by consanguinity. Thirty- 

 one such marriages are reported in the mar- 

 riage records, and of these 14, or 45.1 per 

 cent. , resulted in deaf offspring. One hundred 

 children were born from these thirty-one mar- 

 riages, and of these 30, or 30 per cent., were 

 deaf. It is, therefore, exceedingly dangerous 

 for a deaf person to marry a blood relative, no 

 matter what the character or degree of the re- 

 lationship may be, and no matter whether the 

 relative is deaf or hearing, nor whether the 

 deafness of either or both or neither of the 

 parents is congenital, nor whether either or both 

 or neither of them have other deaf relatives. 



The student of inheritance will, no doubt, 

 be disposed to state this conclusion in more 

 general terms, and to assert that the consan- 

 guineous marriage of one who has any consti- 

 tutional infirmity or defect is imprudent and 

 inadmissible, and that since no one can be sure 

 that both parties to a contemplated marriage 

 are constitutionally sound in all respects, no 

 consanguineous marriage is permissible. 



The writer of this review prepared, by re- 

 quest, some twelve years ago, an essay on the 

 conditions which are necessary for the produc- 

 tion of a deaf variety of the human race, 

 which was printed in the Report of the Royal 

 Commission on the Blind, the Deaf and Dumb, 

 etc. London, 1889. 



In this essay he gave reasons for holding the 



only necessary condition to be that successive 

 generations of persons — either deaf or hearing 

 — with deaf relatives should marry and have 

 children. 



This opinion was so much opposed to the 

 views on inheritance which were current at 

 that day that none of the eminent men of 

 science — seven in number — who prepared essays 

 upon the same subject, gave it any support, or 

 even took it into consideration. Most of them, 

 indeed, held that a deaf variety of the human 

 race may be expected to result from the inter- 

 marriage of successive generations of deaf per- 

 sons. 



Professor Fay's thoughtful and exhaustive 

 analysis of the da taafforded by the records of 

 some 4,500 records of marriages of the deaf 

 shows that the view of the matter which was 

 reached by the writer twelve years ago, on 

 theoretical grounds, turns out to be a fact so 

 soon as it is submitted to a practical test. 



\V. K. Beook^. 



Exploitation technique des forets. Exploitation 

 commerciale des forets. Two Volumes. By 

 M. H. Vanutbeeghe, Ingenieur agronome 

 Garde general des Forets. 8vo. Paris, 

 Gauthier-Villars. 



With the establishment of professional schools 

 of forestry at Cornell and Yale Universities and 

 the promise of others to follow, technical for- 

 estry literature will naturally receive more at- 

 tention in this country than hitherto. Foreign 

 literature, however, except the few standard 

 text-books and the best journals, will hardly at- 

 tract much attention, unless it is essentially 

 new in matter or manner. The two volumes 

 under review bring nothing new in matter to 

 the professional man, but some portions are 

 treated in an unorthodox, independent manner 

 which will appeal to the thinking student and 

 practitioner, even though he may not agree al- 

 ways with the author's views. To find these 

 volumes published as a part of an Encyclopidie 

 scientifique des aide-memoire is rather surpris- 

 ing, for they are by no means, as one would 

 expect, reference books or brief reviews, but in 

 large part rather argumentative and free in 

 style, attempting to impress the author's rad- 

 ical views unbiased by the orthodox tenets 



