SCIENCE 



Friday, Februabt 15, 1918. 

 contents 



The American Association for the Advance- 

 ment of Science: — 



Some Underlying Principles in the Structure 

 of the Nervous System: Peofessos G. H. 

 Parkee 151 



Sollin Arthur Harris 162 



Scientific Events: — 

 Dr. FewTces and the Bureau of American 

 Ethnology; Public Health Administration 

 in Bussia; Natural History Collection for the 

 Welsh Museum; The British Museum and 

 the War 1G2 



Scientific Notes and News 166 



University and Educational News 170 



Discussion and Correspondence: — 

 Luminosity of Sectifier Electrode: Pro- 

 fessor Haevey B. Lemon. An Un- 

 usually Briliant Halo: O. C. Lester. 

 Marking Microscope Slides: Mart K. 

 Bryan 170 



Scientific Books: — 

 Whitehead on the Orgayii^ation of Thought 

 Professor C. J. Keyser 171 



Special Articles: — 

 Soil Moisture and Temperature Factors in 

 the Winter-killing of Grain Crops: S. C. 

 Salmon 173 



MSS. intended for publication and books, etc., intended for 

 review should be sent to 'rhe Editor u{ Science, Gamson-OD- 

 Hudson, N. Y. 



SOME UNDERLYING PRINCIPLES IN 

 THE STRUCTURE OF THE 

 NERVOUS SYSTEM I 

 It has long been recognized that the 

 fundamental problems of the nervous sys- 

 tem are impossible of approach without 

 keeping in view continually the finer struc- 

 ture of the parts concerned. Nervous or- 

 gans are not relatively homogeneous bodies 

 as, for instance, glands are, but are intri- 

 cate systems of conducting paths and end- 

 stations and in this respect are unlike the 

 other organs of the body. This contrast 

 appears clearly in many deficiency tests. 

 If a portion of a gland, such as the pan- 

 creas or the liver, is removed, the loss may 

 be quickly covered by the increased activ- 

 ity of that part of the organ which is left, 

 but the ablation of even a small portion of 

 a nervous organ is often followed by seri- 

 ous and permanent defects, which no 

 amount of activity on the part of the ad- 

 jacent tissue can make good. Thus the de- 

 struction of a small group of the receptive 

 cells in the retina results in a scotoma, 

 which the activity of the adjacent cells is 

 incapable of remedj'ing. Hence it appears 

 that in the nervous system specialization 

 may be said to have reached even to the 

 cells themselves. Such a degree of differ- 

 entiation is to be found in no other organ 

 of the body, except perhaps the reproduc- 

 tive glands, whose sperm cells and egg cells, 

 with their highly individualizing capaci- 

 ties, are separately quite as unique as are 

 many nerve cells. It is, therefore, not sur- 



1 Address of the vice-president and chairman of 

 Section F, American Association for the Advance- 

 ment of Science, Pittsburgh, December 31, 1917. 



