362 



SCIENCE 



[N. S. Vol. XXVIII. No. 716 



this objection it must be remembered that 

 plants have two at least of the qualities 

 characteristic of animals — namely, ex- 

 treme sensitiveness to certain agencies and 

 the power of transmitting stimuli from 

 one part to the other of the plant body. It 

 is true that there is no central nervous 

 system, nothing but a complex system of 

 nuclei; but these have some of the quali- 

 ties of nerve cells, while intercommunica- 

 ting protoplasmic threads may play the 

 part of nerves. Spencer" bases the 

 power of association on the fact that every 

 discharge conveyed by a nerve "leaves it 

 in a state for conveying a subsequent like 

 discharge with less resistance." Is it not 

 possible that the same thing may be as 

 true of plants as it apparently is of in- 

 fusoria? We have seen reasons to sup- 

 pose that the "internal conditions" or 

 "physiological states" in plants are of the 

 nature of engrams, or residual effects of 

 external stimuli, and such engrams may 

 become associated in the same way. 



There is likely to be another objection 

 to my assumption that a simple form of 

 associated action occurs in plants — 

 namely, that association implies con- 

 sciousness. It is impossible to know 

 whether or not plants are conscious; but 

 it is consistent with the doctrine of con- 

 tinuity that in all living things there is 

 something psychic, and if we accept this 

 point of view we must believe that in 

 plants there exists a faint copy of what we 

 know as consciousness in ourselves.^^ 



I am told by psychologists that I must 

 define my point of view. I am accused of 

 occupying that unscientific position known 

 as "sitting on the fence." It is said that, 

 like other biologists, I try to pick out what 

 suits my purpose from two opposite 

 schools of thought— the psychological and 

 the physiological. 



" " Psychology," 2d edition, Vol. I., p. 615. 

 =* See James Ward, " Naturalism and Agnos- 

 ticism," Vol. I., Lecture X. 



What I claim is that, as regards reaction 

 to environment, a plant and a man must be 

 placed in the same great class, in spite of 

 the obvious fact that as regards complexity 

 of behavior the difference between them is 

 enormous. I am not a psychologist, and I 

 am not bound to give an opinion as to how 

 far the occurrence of definite actions in 

 response to stimulus is a physiological and 

 how far a psychological problem. I am 

 told that I have no right to assume the 

 neural series of changes to be the cause of 

 the psychological series, though I am al- 

 lowed to say that neural changes are the 

 universal concomitants of psychological 

 change. This seems to me, in my ignor- 

 ance, an unsatisfactory position. I find 

 myself obliged to believe that the mnemic 

 quality in all living things (which is proved 

 to exist by direct experiment) must depend 

 on the physical changes in protoplasm, and 

 that it is, therefore, permissible to use these 

 changes as a notation in which the phe- 

 nomena of habit may be expressed. 

 {To ie concluded) 



Feancis Darwin 



DOCTORATES CONFERRED BY AMERICAN 

 UNIVERSITIES 



The accompanying table gives the num- 

 ber of doctorates of philosophy and science 

 conferred this year and during the preced- 

 ing ten years by forty-two institutions. 

 In the issue of Science for August 30, 

 1907, will be found the details for the ear- 

 lier years. The numbers for the eleven 

 years have been as follows: 236, 224, 239, 

 255, 224, 270, 289, 325, 326, 327, 366. 

 There has thus been a considerable though 

 irregular increase. Unless the number this 

 year is a chance fluctuation, it represents 

 a gain of 12 per cent, above last year and 

 of 50 per cent, above the figures for six 

 or eight years ago. 



Columbia and Chicago gave more de- 

 grees, 55 and 54, respectively, than have 

 ever before been granted by any institu- 



