502 



SCIENCE 



[N. S. Vol,. LIII. No. 1378 



Tlirougliout the chapter and also in later 

 chapters we are given clearly to understand 

 that the enemy submarine oam.paign was the 

 gravest peril which ever threatened Great 

 Britain. 



Chapter III. tells of Anti-Submarine Opera- 

 tions; and while the volume lacks a dra- 

 matic climax, like Jutland, the reader whose 

 blood runs faister because of heroic deeds, can 

 find in (this chapter stirring records of courage 

 and defiance to the end, by the officers and men 

 on decoy ships, drifters, trawlers and mine- 

 sweepers. 



Chapter IV. describes the Introduction of 

 the Convoy System. There were not enough 

 destroyers to give adequate protection. Re- 

 quests for protection came from every quar- 

 ter, but " the vessels wanted did not exist." 

 At the end of February, 1917, the enemy had 

 130 sulbmarines of all types in home waters 

 and 20 in the Mediterranean. 



A very serious situation followed the sink- 

 ing of so many tankers or fuel oil dhips. 

 These vessels of great length and slow speed 

 presented the easiest of targets for a torpedo 

 from a submerged submarine. The reserve of 

 oil became so perilously low that directions 

 were dssued limiting the speed of warships 

 burning oil. 



Other chapters describe the effect of the 

 entry of the United States, the Patrol Craft 

 and Minesweeping, Production at the Admir- 

 alty — and the Future. 



The impression left on lihe reader is that the 

 big fleets, big guns and big ships were to a 

 certain degree side-tracked; and that the 

 emaller units did most of the work and were 

 the effective factors in winning the war. The 

 Admiral clearly indicates this in an eloquent 

 passage on page 188. 



I regret very deeply that in spite of a strong 

 desire to iindeirtake the task, I have neither the 

 information nor the literary ability to do justice 

 to the many deeds of individual gallantry, self- 

 sacrifice and resource performed by the splendid 

 oflScers and men who manned the small craft. No 

 words of mine can adequately convey the intense 

 admiration which I felt and which I know was 

 •hared by the whole Navy for the manner in which 



their arduous and perilous work was carried out. 

 These fine seamen though quite strange to the 

 hazardous work which they were called upon to 

 undertake quickly accustomed themselves to their 

 new duties; and the Nation should ever be fuU of 

 gratitude that it bred such a race of hardy, skil- 

 ful and eourageoTis men as these who took so 

 great a part in defeating the greatest menace with 

 which the Empire has ever been faced. 



The references to the American Navy, and 

 in particular to Admiral Simis, are most com- 

 plimentary. The laying of the mine barrage 

 from Scotland to Norway indicates how far 

 modern warfare at sea has changed since 1he 

 days when Captain Mahan wrote his treatise 

 on " Sea Power." 



. In the future, the seaplane, greatly devel- 

 oped of course from its present stage, will be 

 the effective unit, both in offense and defense. 

 With perhaps more truth the words of the 

 Admiral regarding specialized training wiU 

 hold for officers of the Air Service 



Alexander MoAdie 



Diseases of Economic Plants. By F, L. 

 Stevens. New York, The Macmillan Com- 

 pany. 



This is a revised edition of a former work 

 under the same title by Stevens and Hall. 

 It will be welcomed not only by the pro- 

 fessional botanists, but also by a very large 

 number of teachers, county farm demon- 

 strators and others who are finding plant 

 pathology a subject of increasing interest and 

 importance. The importance of plant diseases 

 and the very rapid progress of plant pathology 

 makes frequent revision of a work of this 

 kind imperative. The general plan of the 

 work is very similar to the original edition 

 but is somewhat enlarged and has been 

 brought up to date. The author pays a 

 pleasing tribute to our American workers by 

 inserting the pictures of Farlow, Burrill, 

 Halsted, Bessey, Atkinson and E. F. Smith, 

 who are so well known to all students of 

 mycology and plant pathology. 



The discussions are arranged with reference 

 to the crops on which the diseases occur. The 

 diseases are grouped mostly with reference to 



