72 



NATURE 



[January 19, 1Q22 



qualities, the winter fish being of inferior taste 

 and texture. Clearly we must either continue to 

 pack a second-rate product, or discover where our 

 sprats go to in summer, invent methods of catch- 

 ing them, and finally adopt more " fastidious " 

 methods of handling, all of which Dr. Johnstone 

 clearly considers could be accomplished by 

 further research. In contradistinction to the 

 sprat our summer herring is said to be second to 

 none. 



After canning the flavour of the fish improves 

 notably, the raw taste disappearing, the bones 

 softening, and the flesh breaking easily ; this is 

 what is called "maturation," and the time 

 required is from six months to as many years to 

 give the best product. No suggestions or experi- 

 ments to ascertain the cause of this proved satis- 

 factory. It would not seem to be autolysis, for 

 storage at a temperature of 37° C. did not hasten 

 the process. Bacterial change is considered more 

 likely, as spores can withstand a temperature of 

 150° C. if present in oil. Catalysis, however, 

 cannot be ruled out, as the tin of the container is 

 always to some degree dissolved. The whole 

 question of " maturation " in respect to all canned 

 foods is, as Dr. Johnstone says, " of huge prac- 

 tical importance — and of remarkable obscurity." 

 It is certain that no commercial product can be 

 stored for from three to six years and then sold 

 cheaply. 



The whole report is immature, in that the 

 investigations were never made on a sufficient 

 scale to be economically of value, and were pre- 

 maturely closed down. It seems doubtful 

 whether they can profitably be restarted until 

 basal investigations, such as on the nitrogenous 

 composition of the protein of fish in respect to 

 phases of reproductive activity and to the forma- 

 tion of fat, are completed. On freezing and 

 maturation the Food Investigation Board, ^ in the 

 midst of other investigations, had been conduct- 

 ing researches for three years, but it is quite 

 clear that there is plenty of room for less 

 " directed " researches. Either the Fishery 

 Boards should take up the whole problem, directly 

 or through the Food Investigation Board, and 

 vigorously prosecute it — even employing bounties 

 if necessary — with a determination to create a new 

 industry of value to an island nation, or drop 

 it altogether. The Scottish Fishery Board 

 made the export of salt herrings — in 1913 

 8.795)^32 cwts. of value 5,331,042/. — a valuable 

 British industry, by pursuing a consistent, steady 

 policy through several decades. In the twentieth 

 century Government officials seem to have little of 



1 See Report for 1920. (H.M. Stationery Office.) is. 



NO. 2725, VOL. 109] 



the imagination required or to be afraid of the 

 fluctuations of political affairs. They need not 

 be, for surely these developments are national 

 and not political, and such as "the man in the 

 street " — and in the Commons — requires. 



J. Stanley Gardiner. 



Our Bookshelf. 



The Microtomist's Vade-Mecum: A Handbook oj 



the Methods of Microscopic Anatomy. By A. B. 



Lee. Eighth edition. Edited by Prof. J. B. 



Gatenby, with the collaboration of Prof. W. M. 



Bayliss and others. Pp. x + 594. (London: J. 



and A. Churchill, 192 1.) 285. net. 

 The new edition of this well-known work of refer- 

 ence has been completely revised by Prof. 

 Gatenby, who has had the assistance of experts 

 in various branches of microscopical technique, 

 and the result is a volume which is practical, 

 critical, and thoroughly up-to-date. Prof. W. M. 

 Bayliss has rewritten the chapter on staining, and 

 his concise account of the nature of staining and 

 of differentiation gives a clear conception of the 

 physico-chemical facts on which these processes are 

 based. Dr. C. Da Fano has been responsible for 

 the five chapters on neurological technique, which 

 form 100 pages of the book and contain many 

 suggestions drawn from his extensive experience. 

 Dr. A. Drew has rewritten the section on Pro- 

 tozoa, which, in addition to the methods for fixa- 

 tion, staining, etc., gives an account of cultural 

 methods for amoebae ; Dr. W. Cramer contributes 

 a dozen pages on the micro-technique of fatty sub- 

 stances, including a useful summary of the 

 methods to be employed in a complete histo- 

 chemical investigation of fatty cell-inclusions ; and 

 Mr. J. T. Carter has revised the account of 

 methods for the study of teeth and bone. The 

 remainder of the work has been in Prof. G^tenby's 

 hands, and the sections on fixation, chromatin, 

 nucleoli, mitochondria, and the Golgi apparatus 

 are especially noteworthy and helpful in sugges- 

 tions ; mention should also be made of the short 

 account of methods of tissue culture in vitro, 

 which, in the hands of Ross Harrison and his 

 successors, have given such remarkable results. 

 The last chapter has been written for the beginner 

 and gives clear directions for carrying through the 

 preparation of a whole mount of a Daphnia, for 

 making sections of muscle or other tissue of a 

 vertebrate, and for preparing a tadpole for serial 

 sections. ■ ■ '" 



Two recent methods for staining bacteria have 

 been introduced to help those who may be doubt- 

 ful whether certain bodies in tissue are or are 

 not bacteria. Having gone so far, the editor 

 might perhaps consider whether he could include 

 in the next edition the methods for the study of 

 spirochaetes which zoologists nowadays frequently 

 find it necessary to examine. Under Annelids a 

 reference to the preparation and mounting of 

 chaetae would also be a useful additioi'. 



