May 6, 1922] 



NA TURE 



^77 



production which in that case accompanies the 

 rapid oxidation of luciferin ; otherwise the process 

 occurs without the evolution of light. The cold-water 

 extract glows for a time until its luciferin is completely- 

 oxidised, and it may be made reluminescent by adding 

 some of the hot-water extract. 



The bacterial theory of animal light, though possibly 

 consistent with the enzymic one, is based on entirely 

 different data. In its modem form, as an explanation 

 of the phosphorescence of fireflies, glow-worms, and 

 such marine animals as Pyrosoma and certain cuttle- 

 fish, it is due to Italian zoologists, and especially to the 

 work of Pierantoni. Dr. Buchner is a convert to this 

 view and is a worker in this field. He gives a very 

 interesting account of the evidence, which is of a 

 biological, and not, as in the case of the enzyme school, 

 of a chemical character. According to these observa- 

 tions, the luminous organs of cephalopods, be they 

 never so complicated, are essentially cultures of bacteria 

 in media suitable for their nutrition, and in situations 

 favourable for obtaining oxygen. 



In the common Sepia, for example, the organ 

 (hitherto called the accessory nidamental gland and 

 regarded as part of the egg-producing mechanism) 

 consists of a modified part of the mantle within which 

 different kinds of bacteria occur. Some are luminous, 

 others are not. They also occur in the egg membrane 

 before development, and Pierantoni describes the 

 infection of the embryo by bacteria derived from those 

 of the egg capsule. In a similar manner he explains 

 the relationship between the luminosity of the egg 

 of the glow-worm and that of the larva and adult 

 beetle. The cells of the luminous organ of Pyrosoma 

 contain structures that are also apparently symbiotic 

 organisms. Noctiluca, however, has not yet been 

 examined from this point of view. 



The difficulty that many will feel in regard to this 

 or the rival solution of an admittedly complex problem 

 is the incompleteness of the explanation hitherto 

 given of flash and occultation and of the apparent trans- 

 mission of a mechanical stimulus from one part of a 

 luminous animal (as in Pyrosoma) to another, lighting 

 the " lamps " as it travels along. The solution seems 

 to lie in the phases and disturbances not only of 

 respiration, but of other controlling factors leading 

 to continuous or alternating evolution of light. 



Dr. Buchner has performed a signal service by 

 collating much of what is known of intracellular 

 symbiosis in animals, and his book is one that is most 

 suggestive for further experiment and observation. 

 It indicates the fruitfulness of border-line investigation, 

 and should be widely known amongst biologists to 

 whatever section of organic science they may belong. 



F. W. Gamble. 

 NO. 2740, VOL. 109] 



Our Bookshelf. 



Industrial and Power Alcohol. By Dr. R. C. Farmer. 

 (Pitman's Technical Primer Series.) Pp. x+iio. 

 (London : Sir Isaac Pitman and Sons, Ltd., 1921.) 

 2^. 6d. net. 



The author has certainly contrived to include a very 

 large amount of information regarding alcohol in this 

 little book, which contains clear descriptions of the 

 properties of the alcohols and the methods of pro- 

 duction. There are interesting chapters on the 

 technical applications and the use of alcohol for the 

 development of power. By no means the least in- 

 formative part of the book is the numerous references 

 to government regulations and restrictions. Thus, 

 after a statement of some of these restrictions, we 

 read on page 31 : — " Plant is stereotyped, and there 

 is no encouragement to introduce improvements in 

 method or in apparatus. Transport by tank is for- 

 bidden, and no distillery is permitted to be more than 

 a quarter of a mile from a market town, whereas it 

 would frequently be better to situate the distillery 

 near to the raw materials." We can commend this 

 book to any who are interested in the development 

 of alcohol as a fuel. 



Les Combustibles liquides et leurs Applications. Par 

 le Syndicat d'AppHcations Industrielles des Com- 

 bustibles liquides. Pp. iii + 621. (Paris: Gauthier- 

 Villars et Cie, 1921.) 



One may liken this volume to the many similar pocket- 

 book issues extant in this country as compendious 

 guides to the various branches of applied science. It 

 serves a double purpose as an epitome of petroleum 

 technology and as a standard work of reference for 

 immediate requirements in the field, refinery, and office, 

 and although written essentially for the use of the 

 French industries concerned with inflammable liquids, 

 it deserves a much wider sphere of utility. This type 

 of publication, though frequently condemned as 

 inimical to the best interests of scientific work and 

 commercial production, commands a degree of popu- 

 larity for which it is not, perhaps, difficult to account. 



H. B. Milner. 



The Development of Institutions under Irrigation ; With 

 Special Reference to Early Utah Conditions. By Prof. 

 G. Thomas. (The Rural Science Series.) xi + 293. 

 (New York : The Macmillan Company ; London : 

 Macmillan and Co., Ltd., 1920,) 16^. net. 



Prof. Thomas aims at tracing the evolution of water 

 legislation in Utah from 1847, when the Mormon pioneers 

 founded Salt Lake City, to the present time. He shows 

 how the Mormons, if not the first people in America to 

 practise irrigation, were certainly the first to establish 

 it on an extensive scale, the whole of their civilisation 

 practically resting on this type of agriculture. They 

 showed the way to reclaim vast areas of arid land and 

 on their pioneer attempts have been based the 

 methods utilised in other parts of the United States. 

 He also traces the influence of this type of agriculture 

 on the plan and design of the cities of Utah. The book 

 would have been improved by the addition of a map. 



