The Sweating Apparatus 



223 



"Taking the American white soldier 

 as the standard, the number of sweat 

 glands per unit of skin area was found 

 to he 6.83% greater in the American 

 negro soldier, 16.61% greater in the 

 . Filipino soldier, 23.34% greater in the 

 Aloro soldier, 26.81% greater in the 

 adult Negritos, 31.72% greater in the 

 Hindu, and 69.82% greater in the 

 Negrito youths and children. The 

 greater number of sweat glands per 

 tmit area with the Negrito youth and 

 child is no doubt due to a corresponding 

 difference in size of individuals. As all 

 the sweat glands are fully formed at 

 birth it is merely a question of the in- 

 crease in skin area during growth bring- 

 ing about a dispersion of the glands." 



Thus the supposition that evolution 

 has, by natural selection, provided 

 troi)ical races with more sweat glands 

 than the northern races, is borne out by 

 the actual counts. The writers con- 

 clude : 



"We are not able to confirm Aron's 

 observation that the tropical aborigines 

 secrete only small beads of sweat over 

 the entire body. On two tramping 

 expeditions in the mountains of the 

 Philippines which we were fortunate 

 enough to arrange with a number of 

 Negritos we observed streams of sweat 

 running down the back, and copious 

 sweating on scalp, forehead and face and 

 sweat dripping from the chin." 



Research in 



Among the genetics problems under 

 investigation by A. F. Blakeslee at 

 the Carnegie Institution Laboratory, 

 Cold Spring Harbor, L. I. (says the 

 annual report of the institution) are: 

 inheritance of self-sterility in Rudbeckia, 

 Helianthus, and Verbena, parthenocarpy 

 in cucumbers, chemical and physical 



Plant Genetics 



differences between the sexes in dioeci- 

 ous plants, the annual habit in beets, 

 various characters in Geodetia, Clarkia, 

 Portulaca, Fraxinus, Betula, Morus, 

 Populus, and Salix," and particularly the 

 inheritance of mutations in Rudbeckia 

 hirta (15,000 pedigreed plants were 

 grown last year) and Datura. 



A New Handbook of Mendelism 



A MANUAL OF MENDELISM, by 

 Jame,s Wilson, Professor of Agriculture in the 

 Roval College of Science for Ireland, Dublin. 

 Pp.' 152. London: A. & C. Black, Ltd., 1916. 



Professor Wilson first gives a historical 

 review of Mendelism and a description 

 of its fundamental principles, and then 

 in a comprehensive and well-planned 



way outlines the additions and exten- 

 sions which he thinks justified. The 

 book is well written, but some of the 

 most important points are unfortunately 

 supported by evidence, particularly 

 from animal breeding, which seems to 

 the reviewer to be of more than doubtful 

 validity. 



AN INTRODUCTION TO A BIOLOGY, 

 and other papers, bv A. D. Darbishire. Pp. 

 291, price $2.50 net' Funk & Wagnalls Co. 

 360 Fourth Avenue, New York, 1917. 



Air. Darbishire died recently while 

 training for military service in England, 

 and most of his published papers on 

 genetics have been collected in this 

 posthumous volume. The first eighty- 

 eight pages are taken up by the essay 

 which gives the book its title, and which 

 represents the unfinished attempt of the 

 author to interpret the vitalistic biology 

 of Samuel Butler and Henri Bergson. 

 It is agreeably written and stimulating 

 of thought, but unfortunately the part 



A Posthumous Book by Darbishire 



which the author had completed was 

 only introductory, and therefore is 

 suggestive rather than convincing. The 

 other papers deal principally with the 

 supposed conflict between Mendelism 

 and biometry, and are already known 

 to geneticists. While they possess real 

 value, the longest of them are consider- 

 ably out of date. On the whole, the 

 book is not so much a contribution to 

 science as a self-revelation of the frank, 

 idealistic, enthusiastic author, for whom 

 the reader can hardly help carrying 

 away the feeling of warm friendship 

 which it is said was experienced by all 

 who met him during his lifetime. 



