594 



NATURE 



[February 5, 1920 



City. But the promoters could not crystallise 

 the sugar ; they could only make syrup, and 

 before long they gave up the business. The in- 

 dustry was not definitely established until 1890; 

 development was fostered by means of tariffs, and 

 was very rapid during the war. In the early 

 days of the nineteenth century the percentage of 

 sugar in the root was about 5 ; now it is about 

 16-18 per cent. It differs in the different varie- 

 ties, and is affected by the soil and weather con- 

 ditions. Sufficient irrigation in dry seasons in- 

 creases the amount of sugar. 



The great diflgculty in dealing with the crop is 

 the amount of labour involved in lifting. This 

 is now obviated to a considerable extent by the 

 use of suitable implements, two types of which 

 are described. 



The crop is liable to attacks by insect pests and 

 fungi; no fewer than 150 species of insects feed 

 on the beet, of which about forty are of economic 

 importance ; the number of fungus pests is small 

 at present, but it is increasing. 



(4) The last book on the list, on strawberry- 

 growing, is by Prof. Fletcher, of the Pennsylvania 

 State College. The author opens with the state- 

 ment, which will be new to many people, that 

 "the strawberry is distinctly North American. 

 Most modern varieties sprang from species only 

 found in the Americas. Progress in the domestica- 

 tion of the fruit was coincident with the intro- 

 duction into Europe of American types." In 1910 

 the acreage under strawberries in the United 

 States and Canada was 150,000 acres, said to 

 be more than the combined acreage of all other 

 countries. 



Bearing in mind the results of fertiliser experi- 

 ments at the Woburn fruit farm, the English 

 reader turns with interest to discover what 

 results have been obtained in America. Curiously 

 few fertiliser experiments with strawberries seem 

 to have been made. At the Missouri Station 

 phosphates were beneficial, but nitrogenous and 

 potassic manures were harmful. At the Tennessee 

 Experimental Station no fertilisers proved effec- 

 tive. At Cornell phosphates and potassic ferti- 

 lisers were beneficial, while nitrogenous manures 

 were harmful. But the experiments lasted only 

 a year or two, and hence the results do not yield 

 as much information as they might as to the needs 

 of the plant. In nature the strawberry flourishes 

 on an acid soil, and in cultivation lime is not found 

 necessary. 



As usual in the Rural Science Series, the author 



brings into the book information on all aspects of 



the crop, dealing with such diverse subjects as the 



shape of boxes for packing, the raising of new 



NO. 2623, VOL. 104] 



varieties, insect and fungus pests, etc. It is obvi- 

 ous that no one man can be competent to deal 

 adequately with all branches of the subject, but 

 the general treatment is good and gives the prac- 

 tical man all the help he needs; there are also, 

 references to experimental station bulletins, where 

 further information by experts on particular sub- 

 jects can be obtained. 



Some years ago productivity figures were 

 worked out for the farm workers of the different 

 countries of the civilised world. America easily 

 headed the list, which was as follows : — 



America ... ... ... 292 



Great Britain ... ... ... 126 



Germany ... ... ... 119 



France ... ... ... 90 



Italy 45 



Looking through this Rural Science Series, 

 edited by Dr. L. H. Bailey, and seeing how 

 earnestly the authors strive to deal with the con- 

 ditions actually obtaining in the States, we find 

 at least a partial explanation of the striking 

 superiority of the American worker. Such books 

 could scarcely be written in this country as. yet, 

 but there are hopeful signs for the future. A 

 body of young men and young women is gather- 

 ing at the agricultural experimental stations and 

 colleges of this country capable of doing good 

 work that will bear comparison with anything 

 done elsewhere, and there are increasing signs 

 that their work is favourably and respectfully 

 received by the agricultural community. 



E. J. Russell. 



OVR BOOKSHELF. 



The Building of an Autotrophic Flagellate: 

 Botanical Memoirs. No. i. By A. H. Church. 

 Pp. 27. (London, etc. : Humphrey Milford and 

 Oxford University Press, 1919.) Price 2S. 



"The story of the evolution of the plant regarded 

 as expressed in simplest terms as an autotrophic 

 flagellate of the plankton-phase from nothing at 

 all but ionized sea-water " is the subject of Mr. 

 Church's extremely condensed and technical 

 paper. In reality it is rather the requirements of 

 the problem than its solution which Mr. Church 

 indicates, and, whilst he realises the magnificence 

 of the factors with which he has to deal (the sea, 

 for example, is " a medium complex beyond the 

 possibilities of human computation "), he presents 

 the results of much learning in huge unbroken 

 and almost unintelligible paragraphs. Who, for 

 example, would imagine that the following sen- 

 tence refers to the origin of seaweeds from 

 free-floating algae? "In the case of initial 

 benthic organism, the first inception of such a 

 continuous deposit [he is talking of cell-walls] pre- 

 pares the way for the general formula adopted 

 in describing the events in the life of an algal 



