No. 3, April, 1921] GENETICS 249 



1732. Bryn, Halfdan. Researches into anthropological heredity. Hereditas 1: 186-212. 

 1920. — The studies have been conducted in "two much isolated mountain districts" of Nor- 

 way. The paper is in two parts, the first "On the inheritance of eye colour in man." The eyes 

 of 834 individuals were examined through a magnifying glass and two types of eye color 

 distinguished: (1) eyes with "a single layer of black pigment in the back part of iris, appear- 

 ing always blue or gray;" (2) eyes "which besides this pigment also contains a more or less 

 brownish one, which eyes appear brown, green, gray, bluish-brown or blue if the brownish 

 pigment is to be found very scantily." Under the latter type is segregated also a group of 

 "mixed" eyes, which appears to yield at least one biotype. Individuals homozygous for 

 "brown" eyes are "probably very rare in the population," hence the mode of inheritance 

 was not especially studied. In general it was found that "in our population there are prob- 

 ably three biological types with regard to eye-colour; (a) the plain blue type; (b) the plain 

 brown type; (c) the light 'mi.xed' type. These different types interbreed in accord with the 

 Mendelian laws of heredity, viz., blue eyes are recessive to all types of eyes with brownish 

 pigment." — -The second part of the paper treats of "The genetic relation of index cephalicus." 

 The two districts mentioned "differ very much with regard to the size of this index;" one 

 "characterized as rather brachycephalic," having an index of 80.1, the other an index of 

 76.9, while "the average index of the entire country is about 78.0." A careful study of the 

 collected data shows "very plainly that there are at least two types in each of the districts. 

 One is common to both districts. It is the northern fair nucleus," with an index of about 77.5. 

 In one district this is associated with "a dark brachycephalic type," index about 83, and in 

 the other district it is associated with a "dark dolichocephalic type," index about 73. The 

 author concludes that there are here "three biotypes .... with regard to index 

 cephalicus" which interbreed in Mendelian fashion. "The brachycephalic type is dominant 

 to both the others. The dolichocephalic type is too rare to allow any positive conclusions; 

 it seems, however, to be dominant to the mesocephalic type and recessive to the brachy- 

 cephalic type." — Howard J. Banker. 



1733. BuRCH, D. S. Heredity and economical production of food. Jour. Heredity 11: 

 7-11. 2 fig. 1920.^Pointing out the lack of thought and knowledge of the principles of 

 breeding and a discussion of the work of the Federal Department of Agriculture to encourage 

 the application of these principles to livestock and farm crops. — J. H. Beaumont. 



1734. Castle, W. E. Genetics and eugenics. 2nd ed., 15.5 X 23.5 cm., 395 -p., 7 -pi., 155 

 fig. Harvard Univ. Press: Cambridge, Massachusetts, 1920. — 'Second edition shows exten- 

 sive revision with addition of much new matter mainly represented by interpolated chapters 

 on "Genetic changes and the chromosomes," "Genetic changes in asexual reproduction, in 

 parthenogenesis, and in self-fertilization," "Genetic changes in bisexual reproduction," and 

 "Hybrid vigor and heterosis." The author's hooded-rat results are shown to be due to the 

 action of modifying factors, on an unchanged fundamental gene for the hooded character; 

 and blending inheritance, and Johannsen's pure-line principle are also given new treatment 

 which brings the author's position on these subjects into better accord with that generally 

 held by other geneticists. The extensive bibliography which was an excellent feature of the 

 first edition has been brought down nearly to date of publication of the second edition, by 

 the addition of more than 200 titles. — Geo. H. Shull. 



1735. Chamberlain, Charles J. Grouping and mutation in Botrychium. Bot. Gaz. 70: 

 387-398. 11 fig. Nov., 1920. — B. dissectum never occurs except in association with B. obli- 

 quum. In B. dissectum many sporangia are abortive, and many spores of apparently perfect 

 sporangia are obviously abortive, suggesting at least partial, and probably entire, sterility. 

 Botrychium does not reproduce vegetatively; hence B. dissectum must arise from mutating 

 spores (2-5 per cent) of B. obliquum. Direct cultural proof is impossible, since Botrychium 

 spores cannot be germinated artificially. — -Merle C. Coulter. 



1736. Cole, Leon J. An early family history of color-blindness. Jour. Heredity 10: 

 372-374. Fig. 12. Nov., 1919.— The Philosophical Transactions of the Royal Society of 



