48 The Journal of Heredity 



NEW PUBLICATIONS 



SEX: ITS ORIGIN AND DETERMINATION, Ijy Thomas E. Reed, M. D.; 312 pages, 

 $2.50. Rcbman Company, New York, 1914. 



In this well-ad vcrtiscd book the author, a physician, undertakes to supply some 

 new conceptions concerning "The Nature of Life, Reproduction and Sex, the latent 

 bisexuality of all animal life and the primitive hermaphroditism of the germ plasm; 

 the nature and origin of twins, particularly of conjoined twins ; the primitive alter- 

 nating and metabolic nature of sex; the manifestations of lunar rhythms in labor, 

 in infectious disease, their influence on births, deaths, surgical operations, men- 

 struation, gestation and the detcnnination of sex." Obviously a big job. 



The thing that is new in the book is a theory that there is a cycle in animal 

 life, of shorter duration than the well-known monthly cycle, manifested in the germ 

 cells and the developed organism, and having an effect upon the determination of 

 sex as well as on the progress of labor and other vital processes. The lunar day 

 divided into two twelve hour periods, and these in turn divided into two six hour 

 periods — a "positive" and a "negative" — supplies this cycle. A positive period — 

 based on the position of the moon — is one during which the moon passes from the 

 eastern horizon to the zenith, or from the western horizon to nadir. A negative 

 period is one during which the moon passes from zenith to the western horizon, 

 or from nadir to the eastern horizon. The theory further ]jostulates that the ovum 

 is alternatingly male and female, and that the sex that arises from it depends upon 

 the stage the ovum happens to be in when fertilized. If fertilized during a positive 

 period a male results; fertilization during a negative period produces a female. 

 This the author claims practically to have established for the human subject. 



The wonder is, however, that with so wide and extended a practice there were 

 so few cases — about 20 — to cite as evidence and that these were not all cited. 

 And still greater the wonder that with all the energy sjjcnt in digesting literature 

 and in deductive reasoning, the simple ex])edient of recourse to observation and 

 experiment on animals — even domestic animals — was not resorted to. Here the 

 whole theory of alternating herma])hroditism of the ovum and the author's general 

 theory of sex determination would have been quickly disproved. Indeed, merely 

 to have glanced in this direction — without further experimentation — would, as 

 every biologist knows, have been quite conclusive. Whatever the inherent virtues 

 of a tide-table, there is no reason to susj^ect that within it there lurks the sentence 

 of sex. Oscar Riddle. 



HEREDITY AND SEX, l^y Thomas Hunl Morgan, Pli.D., New York, Columbia University 

 Press, 1913. Pp. xi + 282, $1.75 net. 



This book of Dr. Morgan, professor of experimental zoology at Columbia Univer- 

 sity, is the standard authority on the relations between heredity and cytological 

 research. It discusses in detail the recent microscopical studies of the cell and its 

 chromo.somes, and the Mcndelian theories, as inter])rcting heredity, and i)artic- 

 ularly, of course, the inheritance of sex. The author considers as exjjloded the 

 idea that external conditions determine sex, believing that it is detennined through 

 the internal mechanism of the cell itself, as a result of the laws of chance. He 

 explains some of the contradictory results published by other exijcrimenters by 

 saying, "the environment may slightly disturb the regular working out of the two 

 possible combinations that give sex male or female. Such disturljanccs may affect 

 the sex ratio but have nothing to do with sex determination." 



