November 18, 1910] 



SCIENCE 



719 



of consciousness in general, in the lower forms 

 of animal life, that it may be well to remind 

 ourselves of its analogy with the fact that the 

 facial expressions produced by sweet and bit- 

 ter tastes have been noted in an infant whose 

 cerebral hemispheres were lacking. We do 

 not regard the reflex production of these facial 

 movements under abnormal conditions as in- 

 ■compatible with their being normally the ex- 

 pression of conscious process : why then should 

 the squirming movements of the detached 

 hinder end of a worm prove that such move- 

 ments are not normally the accompaniment of 

 pain sensation? The author uses as an a 

 priori argument against the existence of pain 

 sensations in animals of low structure the 

 ■consideration that such sensations would be of 

 no use to an animal like the earthworm, for 

 the function of pain is to serve as a warning 

 enabling an animal to avoid harmful stimuli 

 in the future. " A mammal that has been 

 liurt by a man will fear and so far as possible 

 avoid man in the future, but an earthworm 

 •can neither recognize nor avoid man." This 

 reasoning seems highly superficial, in view of 

 the fact that recent work on the lower inverte- 

 brates has shown that reactions of anticipa- 

 tion, where one stimulus comes to serve as a 

 " warning " of another, causing the avoiding 

 reaction to be made before the second and 

 injurious stimulus arrives, are found even in 

 animals as low as the sea-anemone. 



To the higher mammals, however, Ziegler 

 ■would not deny the possession even of memory 

 ideas, and it is amusing to find him quoting 

 Ament's wholly uncritical observation on the 

 ■dog that licked the ice off the window pane 

 and looked out, as evidence that " ideas of 

 .ends " are present in the mind of a higher 

 animal. Truly it is hard to be consistent in 

 one's use of facts as evidence when one is 

 guided by a priori considerations. The essen- 

 tial difference between the human mind and 

 that of the other mammals Ziegler holds to be 

 the possession of abstract ideas. 



One of the later sections of the essay gives a 

 brief account of the author's theory that ac- 

 <iuired or " embiontic " pathways in the nerv- 

 ous system depend " on small and slow 



changes (of form and especially of thickness) 

 in the ramifications of the cell processes, as 

 well as on the formation of paths within the 

 cell-body (formation or strengthening of 

 neurofibrils)." 



The appendix on the brain of ants and bees 

 is explanatory of some plates from models by 

 Ziegler's pupils. 



Margaret Floy Washburn 



Vassar College 



y 



THE PROBLEM OF ELEMENTAL LIFE 

 Eec'ent investigations on the part of certain 

 physiologists and histologists tend to throw 

 some new light upon perhaps the greatest of 

 all scientific and philosophical questions, the 

 problem of life and death. Whereas until re- 

 cently the transition from the state of life to 

 that of death was considered, at least by the 

 medical and legal profession, to occur at the 

 moment when the heart stopped beating, re- 

 cent observations tend to show that besides 

 this general conception of life and death, there 

 exists also an entirely different form of life, 

 an elemental life of the tissues, which under 

 certain conditions may continue for long 

 periods after the general life of the animal 

 has ceased, after the heart has stopped beating 

 and the personality of the individual has been 

 lost. The elemental death begins, under nor- 

 mal conditions, promptly after general death 

 has occurred and is caused by the two factors 

 of bacterial invasion and ferment activity, the 

 change manifesting itself by loss of cell ten- 

 sion and alterations in cell form, the first steps 

 toward putrefaction and dissolution. If, how- 

 ever, immediately after general life has ceased 

 to exist, fragments of tissue are removed from 

 the body and placed in such a condition as to 

 prevent bacterial or ferment action, the ele- 

 mental life of the tissue may be maintained 

 over long periods of time. Such a life is 

 latent; it shows no signs of vital activity; 

 upon such a piece of tissue being replaced in 

 the animal body and its nutrition being main- 

 tained by a renewal of the circulation, life 

 again becomes manifest, and the tissue renews 

 its functional activity as a part of the living 

 organism. 



