Al-GVST 14, 1903.] 



SCIENCE. 



209 



esses. It has thus been difficult for the stu- 

 dent of physiology who is not at the same 

 time well versed in physical chemistry to ob- 

 tain the information required for the prose- 

 cution of work in this field. Secondly, it 

 seemed desirable to bring together in a general 

 review the literature of this subject iiu its 

 biological aspects, so that the promising and 

 unpromising points for future research might 

 become more apparent." 



Opening the book, we find that it consists 

 of two parts; the first of forty-eight pages 

 devoted to ' Physical Considerations.' This 

 includes what are properly physical discus- 

 sions. There is first a discussion of matter 

 in its several states, and this is followed by a 

 chapter on diffusion and diffusion tension. 



The third chapter is devoted to ' Liquid 

 Solutions,' the fourth to ' Ionization ' and the 

 ficfth and sixth to ' Osmotic Phenomena.' In 

 the treatment no attempt has been made to 

 be exhaustive. Only certain aspects of the 

 present conceptions of these matters among 

 physicists and chemists are discussed, and 

 their discussion is presented with the aim of 

 clearing the way for the physiological dis- 

 cussions which make up the body of the book. 

 The author especially disclaims any origi- 

 nality in this portion of his book, but it must 

 be said that he has done a very great service 

 to botanical science by making available here, 

 for the first time, a summary treatment of 

 these physical phenomena. 



Part II. is devoted to ' Physiological Con- 

 siderations,' and here in about one hundred 

 pages the botanist will find some important 

 discussions. The author first takes up ' Tur- 

 gidity.' and follows this with a discussion of 

 * Absorption and Transmission of Water and 

 Solutes,' ' The Influence of Osmotic Pres- 

 sure on Organisms.' The treatment is emi- 

 nently satisfactory and will prove to be very 

 helpful to the physiological student. To show 

 the range of the discussion in the book we 

 may quote from the author's summary at the 

 close of the book as follows: 



As far as investigation has gone, it has been 

 found that growth is accelerated in weak solu- 

 tions and retarded in concentrated ones. The 

 terra ' growth ' here includes, not only enlarge- 



ment, but also the process of cell division. Also, 

 in some cases at least, the direction of new walls 

 is profoundly influenced by the concentration of 

 the surrounding medium. In general, all vital 

 processes are retarded in concentrated solutions. 

 Reproduction, being a peculiar form of cell divi- 

 sion, appears in some cases to be entirelj' depend- 

 ent upon the osmotic pressure of the surrounding 

 medium. Irritability is also greatly influenced 

 by external pressure. Not only is this function 

 retarded in concentrated solutions, but in some 

 forms tlie direction of response to a given stimulus 

 may be reversed by a sudden change in the osmotic 

 surroundings. The comparative concentration of 

 the external and internal solutions acts, in many 

 cases, as a stimulus upon the organism, giving 

 rise to the phenomena of osmotaxis. 



All the effects of high concentration of the 

 surrounding liquid seem to be due to extraction 

 of water from the living cells. They may be due 

 either to a drying-out process or to decrease in 

 turgidity. That they are sometimes due to the 

 former is proved by curious analogies between 

 the various processes which extract water from 

 the protoplasm. Whether or not this extraction 

 of water from the protoplasm itself is the direct 

 cause of the responses to concentrated solutions, 

 is not yet known. The effect may be a chemical 

 one, due to the increased concentration of the 

 contained solutions. 



This book will at once take its place as a 

 standard work in all institutions where any 

 attention is given to plant physiology. 



Charles E. Bessey. 



The U-vnERsiTy of Xebraska. 



SCIEXTIFW JOURNALS AND ARTICLES. 



THE AMEBICAN JOURNAL OF ANATOMY, VOL. II., 



NUMBER 3. JULY, I9o3. 



A. M. Mtlleb: 'The Development of the Post- 

 caval Vein in Birds,' pp. 283-299, with 10 Text- 

 figs. 



G. L. Streeter: 'Anatomy of the Floor of the 

 Fourth Ventricle,' pp. 299-315, with 4 Plates and 

 2 Text-figs. 



F. P. Mall: 'The Circulation through the Pulp 

 of the Dog's Spleen,' pp. 315-333, with 1 Plate and 

 1 Text-fig. . 



F. P. Mall: 'The Transitory or Artificial Fis- 

 sures of the Human Cerebrum,' pp. 333-341, with 

 1 Table. 



A. J. Carlson: 'Changes in the Nissl's Sub- 

 stance of Nerve Cells of the Retina of the Cormo- 



