4:70 PROGRESS OF SCIENCE IN THE CENTURY. 



the psychological one, since that afforded by physi- 

 ology seems to us inadequate to fit the facts. 



Another View. — As we wish that our historical 

 balance-sheet, necessarily condensed, should be at 

 least fair, we may direct the reader^s attention to the 

 work of Prof. Loeb (already cited as an instance of 

 the purely physiological position). According to Loeb, 

 reflexes may occur without a reflex arc, they are not 

 necessarily bound up with the central nervous system 

 or the ganglion-cells; the central nervous system is 

 only a convenient conductor; instincts are bundles 

 of tropisms ; neither for spontaneous activity nor for 

 co-ordination are ganglion-cells essential; the only 

 specific function of the brain, or certain parts of it, 

 which Loeb has been able to find, is the activity of 

 associate memory; and this is made possible by pe- 

 culiarities (still quite obscure) in the nature of the 

 colloidal substances which form the physical basis of 

 life. 



DEVELOPMENT AND EVOLUTION OF MIND. 



" We may define psychology," says Dr. G. F. 

 Stout, " as the science of the development of mind." * 

 The definition indicates the modern outlook of the 

 science, but the problems involved are so difficult that 

 we have restricted ourselves to pointing out the vari- 

 ous sources of information. 



The Data. — From four sets of facts the psycholo- 

 gist may obtain development and material for his 

 conclusions as to the individual and racial evolution 

 of mind. 



* Analytic Psychology, Vol. I., 1896, p. 9. 



