CURRENT LITERATURE 
BOOK REVIEWS 
Mendelism. 
A book by BarTEson entitled Mendel’s principles of heredity* has recently 
appeared from the Cambridge Press. The work is divided into two parts. The 
first part is a compilation and summary of all Mendelian work to date. The 
second part contains a biographical sketch of MENDEL and a translation of his 
two classic papers on hybridization in Pisum and Hieracium. The latter also 
appeared in the celebrated Defense of Mendel, published by the same author in 
1g02. 
The body of the work is occupied with an account of the facts of Mendelian 
inheritance, as they have been accumulated since the work of MENDEL was 
brought to the attention of the scientific world at the beginning of the century; 
and a considerable proportion of this work is the result of the activities of 
BATESON and his students. e first three chapters contain the principles of 
Mendelian theory, as they have been developed and modified. The next five 
chapters deal with the phenomena of color heredity, indicating the prominent 
and explanations suggested. Other chapters are concerned with heredity and 
sex; Mendelian inheritance in man; intermediates between varieties; Mendelian 
conceptions of the nature of units; the nature of segregation, reversion, variation, 
etc.; and the final chapter of part I is devoted to the practical application of Men- 
delian principles. The last chapter will prove useful to practical. breeders of 
plants and animals, for even if there is not an actual segregation of characters, it is 
undeniably true that in many cases characters behave as though a segregation and 
recombination according to chance had taken place. There are certain cases, 
however, in which it is very difficult to suppose that a segregation takes place at 
the time of chromosome reduction. Such a case is that of two White races of sweet 
pea, one having long pollen and the other round. In the F; of this cross all the 
hybrids have long pollen, while if a segregation of characters had taken place 
during reduction, we should expect to find in each tetrad of pollen grains two long 
and two roun 
The = honest aspects of Mendelian ee are but lightly touched upon in this 
work, since the author intends to deal with these in a separate volume. The 
remarks on every page, however, as well as the brief discussion of these topics 
leave no doubt as to the interpretation placed upon the phenomena described. It 
* BaTEson, W., MENDEL’s principles of heredity. 8vo. pp. xvit 396. pls. 0, 
colored. pls. 3, half-tone portraits of Mendel. figs. 37. Cambridge: University siew 
New York: G. P. Putnam’s Sons. 1909. $3.50. 
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