AGRICULTURAL BOOK REVIEWS 



GAGER, CHARLES STUART— CoM«n!/e</ 

 heredity and evolution from the strictly botan- 

 ical point of view. The author begins quite un- 

 expectedly vs^ith two chapters on the life-history 

 of a fern, and this concise account, followed by 

 a chapter on fundamental principles, forms a 

 background for the treatment of the subject 

 proper. The definition of heredity as "the gen- 

 etic relationship that exists between successive 

 generations of organisms" omits to recognize the 

 fact that the conception of heredity is funda- 

 mentally concerned with resemblances and dif- 

 ferences as they occur in genetically related or- 

 ganisms. Later chapters deal with Mendelism, 

 evolution, Darwinism, and experimental evolu- 

 tion. A very good balance is preserved Ijetween 

 the historical and the descriptive methods, with 

 a sprinkling of illustrations, the majority of 

 which are new to text- books. 



A chapter on the evolution of plants touches 

 upon such problems as alternation of genera- 

 tions, evolution of the sporophyte, and the evi- 

 dence from comparative anatomy, and ends with 

 a hypothetical ancestral tree of relationships. 

 One of the subjects best treated is that of geo- 

 graphical distribution, which discusses the 

 means of dispersal, peculiarities of distribution, 

 effects of glaciation and cultivation on distribu- 

 tion, endemism, the "age and area" hypothesis 

 of Willis, etc., with numerous illustrative cases 

 from the recent literature. The final chapters 

 deal with the fossil record and the various hypo- 

 thetical relationships of the groups of vascular 

 plants. — Nature 



HAAS, PAUL, AND HILL, THOMAS GEORGE. 



Introduction to the chemistry of plant 

 products. V. 1, 3d ed '20 Longmans $5.50 



21-537 

 "First appeared in 1913. From its first ap- 

 pearance it has been recognized as a book 

 filling a long felt want. It was intended to 

 supply the botanist, and especially the plant 

 physiologist, with chemical knowledge and 

 methods not found in the ordinary text- 

 books on chemistry. It has filled its 

 purpose admirably. Although w^ritten primarily 

 for the plant physiologist, the avoidance 

 of a technical method of treatment makes 

 it a useful book for the botanist of limited 

 chemical training, who is working on problems 

 involving a knowledge of pilant materials. Thus 

 at the present time, when the synthetic view- 

 point of botany in relation to the other sciences 

 is coming to the front, when it is coming to be 

 recognized that botany and chemistry must 

 unite forces in solving many problems, the 

 method of treatment used in the book has in- 

 creased significance. 



The major changes in the book have been 

 made in the chapter on pigments. This chap- 

 ter has been entirely rewritten and much new 

 material incorporated, especially in the part 

 dealing with chlorophyll. A few other im- 

 portant additions have been made to the text, 

 and a number of references have been added 

 to the literature, all serving to bring the work 

 up to date. It will continue to be a book 

 which the plant physiologist and anyone in- 

 terested at all in the chemistry of plant 

 materials will want on his shelf." S. V. Eaton 

 in Bot Gaz 71:156 F '21 



HARDY, MARCEL E. Geography of plants. 

 '20 Oxford $3.00 Agr20-1835 



The author of this comparatively short volume 

 has dared much in attempting to write a brief 

 account of the plant geography of the earth. 

 In most works devoted to the subject authors 

 are usually content to describe the different 

 plant societies, such as forests, grasslands, and 

 the like and mention a few well-known ex- 

 amples of each in the different countries. 

 Schimper'.*? monumental book on plant 

 geography is built on this plan, but the author 

 of the book under review boldly adopts the 

 more interesting, if somewhat hazardous, 

 method of taking the different continents one 

 at a time and briefly describing the vegeta- 

 tion of each. 



It is obviously impossible to give in a short 

 review the scope of the book, for to do so 

 would involve useless repetition of material 

 from the book itself, and it were better for 

 the prospective reader to go directly to the 

 source. No other book in English comes within 

 measurable distance of doing so well what it 

 attempts to do. For here both the botanist 

 and intelligent layman will find in plain Eng- 

 lish a readable account of the vegetation of 

 the different parts of the earth. 



So far as our own continent is concerned 

 the treatment is all that one could expect in 

 a book admittedly general in its scope. The 

 different forest and grassland and desert 

 regions of the continent are dealt with in 

 some detail, but the chief value of the book 

 is that it gives to those who will not or often 

 cannot take the time to study more special 

 works, a clear, readable, and judging by the 

 account of our own vegetation, a reasonably 

 accvirate description of the vegetation of the 

 earth. No specialist will go to such a book 

 for his inforihation, but the general botanical 

 reader may be congratulated upon having in 

 it the best short account of the subject that 

 has appeared. Norman Taylor — Torreya 



HARRIS, FRANKLIN STEWART. Soil alkali, 

 its origin, nature, and treatment. '20 Wiley 

 $2.50 20-15790 



"An excellent critical little book on soil alkali. 

 The author says: 'It has been estimated that 

 about 13 per cent of the irrigated land of the 

 United States contains sufficient alkali to be 

 harmful. This means that there are over 

 9,000,000 acres of land under present canal sys- 

 tems that are affected with alkali. There are 

 many more million acres of alkaline land in 

 the United States that do not lie under irriga- 

 tion systems. The alkali problem is one of 

 no inean importance to farmers, nor to any 

 who are interested in the world's food supply. 



In a strictly chemical sense the word alkali 

 refers to a substance having a basic reaction. 

 As applied to the soil, however, this restricted 

 meaning does not hold, and alkali refers to any 

 soluble salts that make the soil solution suf- 

 ficiently concentrated to injure plants. This in- 

 cludes the chlorides, sulphates, carbonates, and 

 nitrates of sodium, potassium, and magnesium, 

 and the chloride and nitrate of calcium. The 

 sulphate and carbonate of calcium are not suf- 

 ficiently soluble to be injurious to crops. Most 

 of the alkalies are in reality neutral salts. It 

 may be somewhat unfortunate to use for general 

 substances a word that has become so well 

 established in agricultural literature that it 

 would now be very difficult to change it.' The 

 author also emphasizes the great number of 

 purely scientific problems connected with alkali 

 soils and the need of much fundamental re- 

 search in this field."— Bot Gaz 71:157 F '21 



The book includes 16 chapters: 1. Introduc- 

 tion; 2. Geographical distribution; 3. Origin of 

 alkali; 4. Nature of alkali injury to plant; 5. 

 Toxic limits of alkali; 6. Native .vegetation 

 as an indicator of alkali; 7. Chemical methods 

 of determining alkalis; 8. Chemical equilibrium 

 and antagonism; 9. Relation of alkali to 

 physical conditions in the soil; 10. Relation of 

 alkali to biological conditions in the soil; 11. 

 Movement of soluble salts through the soil; 

 12. Methods of reclaiming alkali lands; 13. Prac- 

 tical drainage; 14. Crops for alkali land; 15. 

 Alkali water for irrigation; 16. Judging alkali 

 land. 



HARROW, BENJAMIN. Vitamines; essential 

 food factors. '21 Dutton $2.50 21-2304 



"This book contains 219 pages. The first 

 half of it is devoted to the other food factors 

 and their various interrelations. Following an 

 exhaustive consideration of the vitamines, 

 there are tables showing their distribution in 

 the commoner foodstuffs, a memorandum is- 

 sued by the British committee on accessory 

 food factors in 1919 for the guidance of those 

 engaged in administration of food relief to 

 famine- stricken districts, and an extensive 

 bibliography." — N Y Tinjes 



