SPECIES IDENTITY OF NUCLEUS-PLASMA NORM 449 



their reaction must be quantitative as well; therefore, the law 

 can not be conceived otherwise than of universal application to 

 nerve cells, type by type. At least that it holds for such wide 

 extremes of animal life justifies a formal statement, and, until 

 the exceptions be satisfactorily proved, one must folFow the lead 

 which is offered. This paper is written with the hope that the 

 plain bearing of the results on obscure problems in biology will 

 stimulate work by others. Many facts are needed and it will 

 take a multitude of investigators to gather them. 



SOURCE OF MATERIAL 



The data of age and size of the animals are set forth in table 1 

 along with the measurements of cells, since it is necessary to 

 consider their correlation closely. Resulting partly from the 

 convenience of using material on hand and partly from choice 

 limited by circumstance, a more heterogeneous assortment of 

 animals could hardly be gathered together. The single condition 

 of ineligibility imposed was the frank existence of functional 

 depression. It is felt that the wide range of material goes far 

 in offsetting what is in relation to a whole species a scant number 

 of individuals. The material includes dogs of all weights from 

 1 kgm. to 20; of all ages from six weeks to obvious old age; of 

 both sexes; of different grades of nutrition; of the most mixed 

 breeds, though in a few one strain strongly predominated; and, 

 finally and most important, of a wide range of functional states. 

 For the sake of the emphasis proper for function, there may be 

 specified : six nonnal animals showing various grades of activity 

 from every-day life; two animals in constitution so weak that 

 they succumbed to a few whiffs of an anesthetic; an animal 

 exercised vigorously in a treadmill; an animal in which similar 

 physical exercise preceded the shock of an hour's surgical oper- 

 ation whose final feature was complete exsanguination; three 

 animals dying by accident in the course of different surgical 

 operations ; an animal some four weeks after a craniotomy whose 

 purpose was to resect certain cerebellar fibers; and lastly an animal 

 which received a large dose of lactic acid, a dose however in- 

 effectual in producing frank anatomical depression. 



THE JOURNAL Of COMPARATIVE XEUROLOGY, VOL. 24, NO. 5 



