604 



SCIENCE 



[N. S. Vol. XXXVII. No. 955 



masses, but could scarcely be considered of 

 bacterial grade. Certainly all undoubted 

 Protozoa are of the cellular grade and are 

 characterized by nuclei more or less different 

 from typical nuclei of tissue cells. 



The discussion on syngamy and sex, al- 

 though slightly halting in argument, is ad- 

 mirably presented. Minehin apparently fa- 

 vors the rejuvenescence theory, but finds a log- 

 ical difficulty in the phenomena of partheno- 

 genesis and autogamy and has apparently 

 overlooked some recent work on variations as 

 an outcome of amphimixis, as well as works 

 recording failures to rejuvenate after conju- 

 gation in cultures. This general problem, 

 however, has been so recently re-opened that 

 the literature may not have reached him in 

 time to be incorporated. 



In dealing with the flagellates, especially 

 the blood-dwelling forms, Minehin is perfectly 

 at home and speaks with a first-hand knowl- 

 edge that carries conviction. The life his- 

 tories of the Trypanosomas and other hasmo- 

 flagellates are given with a firm touch and 

 many of the facts are from his own hitherto 

 unpublished results. 



In the section on general physiology the 

 usual physiological activities are concisely, 

 but well, treated. The matters of degenera- 

 tion, regeneration, and the phenomena of de- 

 creasing vitality in Protozoa are somewhat 

 disappointing in the mode of treatment; so 

 also is the neglect, throughout the volume, of 

 evidence derived from the study of various 

 types of Protozoa by the bacteriological cul- 

 ture methods, which for certain groups of the 

 Protozoa, notably the Amoebse, promise to 

 throw a flood of light on the vexed question of 

 pathogenic species. It is most uncharitable, 

 however, to cavil over these minute defects, if 

 indeed they are defects, when the vast and 

 rapidly growing literature on the Protozoa is 

 so admirably welded together in a readable 

 whole, and we shall have occasion many times 

 repeated, to thank the author for his labor, 

 his critical insight, and for the judicious care 

 with which he has selected the material em- 

 bodied in this volume. 



Gary N. Calkins 



Food in Health and Disease. By Nathan S. 



Davis, Jr., A.M., M.D. P. Blakiston's Son 



& Co. 1912. Second edition. Pp. 449. 



It is fair to assume from a statement in the 

 preface that the author expects this work to 

 be used in the instruction of physicians and 

 nurses. It would seem desirable that any pub- 

 lication to be used in this way for instruction 

 in the principles of nutrition should present 

 the latest and most reliable knowledge. This 

 volume fails to meet this requirement. Not 

 only does it contain many statements which 

 must be regarded as erroneous, but some of the 

 most important advances in our knowledge of 

 food chemistry and metabolism receive no 

 consideration. 



One looks in vain, for instance, for a dis- 

 cussion of the recent additions to our knowl- 

 edge of the efiiciency of individual proteins for 

 constructive and maintenance purposes. Os- 

 borne and Mendel have shown that the alco- 

 hol-soluble protein of maize, when it is the only 

 protein fed and is supplemented by the other 

 classes of nutrients in efficient forms, does not 

 serve to maintain life, much less build tissue. 

 Marked differences are observed in the efii- 

 ciency of other proteins. Without question, 

 the influence of certain food substances upon 

 the secretion of the digestive fluids should 

 also receive extended attention in a study of 

 dietetics. It would seem that whoever is to 

 assume the direction of the diet of the well 

 and the sick should have some inkling of this 

 most important new knowledge. 



It is easier to be charitable toward omis- 

 sions of this kind, however, than towards in- 

 accuracies and looseness of statement. It is 

 fair to inquire what justification there is for 

 the statement that carbon dioxide " aids di- 

 gestion by promoting chemical changes and 

 muscular activity." The statements that 

 " tissue waste is most rapid under a protein 

 diet," " that nitrogenous food in greater quan- 

 tities than are strictly needed to maintain ni- 

 trogen equilibrium will cause a waste of tissues 

 as well as repair," and " in other words, aU 

 changes are stimulated by proteins," are most 

 surprising. It is true that the body tends to 



