REVIEWS 503 



Existing textbooks, say the authors, have all emphasised animal genetics more 

 strongly than the student of botany needs. The authors certainly do their best to 

 avoid this state of affairs, but it is doubtful whether the value of a textbook on 

 genetics is improved by the elimination of all reference to animal work that can 

 possibly be avoided. Plant and animal genetics have developed as one subject, 

 and the principles of genetics have been evolved jointly from plant and animal 

 studies. Also it is no bad thing for the student of plants to come into contact 

 with animal science. Moreover, the authors themselves, in spite of their best 

 intentions, cannot keep the animal out, for they deal with Castle's and Jenning's 

 work on modification of unit characters in rats and protozoa respectively, with 

 Morgan's work on linkage in the fruit fly, and with the work of Riddle and others 

 on sex determination in animals. 



The greater part of the book is in reality an elementary though comprehensive 

 survey of Mendelism and its consequences. After the first three chapters, 

 entitled Introduction, Early Theories of Heredity, and Inheritance of Acquired 

 Characters, the elementary facts of Mendelism are stated in Chapter IV., entitled 

 Mendel's Law. In the next five chapters the developments of Mendelism since 

 the rediscovery of Mendel's Rule in 1900 are dealt with under the heading 

 " Neo-Mendelism "—a term for the introduction of which it is difficult to see the 

 necessity. In the following chapters a number of topics are considered from the 

 Mendelian point of view, including Parthenogenesis and Vegetative Apogamy, 

 Self Sterility, and Hybrid Vigour. The book closes with chapters on Sex 

 Determination and The Bearers of Hereditary Characters. 



The authors evidently consider biometrical methods valueless or outside the 

 scope of their work, as they are not mentioned. But one is surprised to find no 

 mention of the interesting question of graft hybrids, which surely comes within the 

 scope of genetics, although the authors discuss the somewhat allied question of 

 •somatic segregation. The book is clearly written and the facts and theories 

 of Mendelism ably stated. It will no doubt form a useful introduction to the 

 study of Plant Genetics for the class of students for whom it is written. 



The merits of the book make one regret the more, the unfortunate feature 

 of it, that to readers unacquainted with genetics something of a wrong impression 

 may be given as to those who are responsible for the development of the subject 

 into the important position it occupies to-day. It is true that the work of Correns 

 is referred to on a few occasions, but the majority of the pioneers of Mendelism 

 are passed over. This would not matter so much if the authors avoided naming 

 all workers on the subject, although such a course might not result in a work of any 

 value ; on the contrary they do not hesitate to quote some of the later workers in 

 this field. Now, undoubtedly, to no one does the development of Mendelism owe 

 more than to Bateson, but he occupies a very inferior position in Plant Genetics, 

 and even the title of his MendeVs Principles of Heredity is cited incorrectly. 

 There is only slight mention of the really classical work of Bateson's school on 

 flower colour, which includes that of Bateson and Punnett on Sweet Peas, that of 

 Miss Saunders on Stocks, and that of Miss Wheldale on Antirrhinum. Tschermak, 

 one of the rediscoverers of Mendel's Rule, is not even mentioned. It was shown 

 by de Vries in 1900, by Correns in 1901, and by the late R. H. Lock in 1904, that 

 starchy endosperm in maize is dominant over sugary endosperm. Yet this 

 question is introduced in Plant Genetics with the statement (p. 46), " East, in 

 crossing starchy and sweet corn, obtained all starchy in the Fi generation, 

 followed by the usual 3 : 1 ratio in the F 2 ." But the authors show no lack of 

 appreciation of East's work as, according to the index, his name is mentioned 



