July 19/1907] 



SCIENCE 



77 



gen." Mathews^ says that " Eespiration is in 

 fact tte dissociation of water witli tte libera- 

 tion of hydrogen." In recent school test- 

 books there are also wide differences. " The 

 entire process of respiration consists simply 

 of an exchange of gases through a membrane " 

 (Linville and Kelly'). " This oxygen eon- 

 sumption is the respiration of plants " (Ber- 

 gen and Davis"). " The process by which 

 oxygen is taken into the body and carbon 

 dioxide is given off is respiration" (Atkinson"). 

 " The escape of carbon dioxide, which follows 

 the taking in of oxygen, is the superficial 

 indication that the very important process 

 called respiration is going on . . . just what 

 happens in respiration is very uncertain, but it 

 involves a series of changes in the living sub- 

 stance itself" (Coulter''). These fragmentary 

 quotations sufficiently demonstrate the differ- 

 ent points of view. Hough and Sedgwick,' 

 in a book which will help to raise the quality 

 of physiology-teaching in our schools, have it 

 that " breathing is not the fundamental act 

 of respiration; . . . this cell breathing is the 

 essential act of respiration, for respiration is 

 only another name for the oxidative processes 

 of the living body " ; but later we find, " The 

 consumption of oxygen and the production of 

 carbon dioxide thus involve an interchange of 

 these gases between the blood and the tissues 

 (internal respiration) on the one hand, and 

 between the blood and the air in the lungs 

 (external respiration) on the other." This 

 latter statement is similar to what may be 

 found in most of our school physiologies, and 

 for that reason alone would best define respira- 

 tion as understood by the great majority of 

 school and college students. 



On the whole this conception seemsi to be 

 the right one. It has the endorsement of the 

 great majority of writers on physiology, while 

 custom, the dictionary, and the etymology of 

 the word strongly support it. The present 



'Biol. Bull., Vol. VIII., May 6, 1905. 



'"Text-book in General Zoology," 1906. 



""Principles of Botany," 1906. 



= " College Botany," 1905. 



' " A Text-book of Botany," 1906. 



' " The Human Mechanism," 1906. 



confusion is largely due to the efl'ort to change 

 the meaning of a word that has long been in 

 general use, an effort that as yet seems to be 

 confined to a few plant physiologists. 



It is very desirable that the common char- 

 acteristics of living organisms should not be 

 lost sight of and that botanical physiology 

 should not have a different terminology from 

 zoological. It is also desirable that the lan- 

 guage spoken in the laboratory should not 

 differ from that which can be properly used 

 outside. Dr. Shaw says, " To define respira- 

 tion then as a gaseous exchange is to turn 

 away from the all-important process." "We 

 can not agree with this " telling objection." 

 As long as there is such a thing as this pe- 

 culiar gas exchange some word will be needed 

 for it ; " respiration " is evidently that word 

 and should no more turn us away from the 

 vital process than " excretion," " alimenta- 

 tion " or other words necessary to describe the 

 superficial phenomena. While respiration is 

 not fundamental it is by no means unessen- 

 tial; from many points of view it is more 

 important than the disruptive processes within 

 the cell. In the study of anatomy, of adapta- 

 tions, of habits, and of ecology in its widest 

 sense the nature of the gas exchange and the 

 means by which it is accomplished become of 

 dominant importance. 



If the word respiration is to be shifted to 

 the energy-releasing process within the cell 

 some new word will be needed to cover those 

 processes now understood under that term. 

 It would be interesting to know if the mean- 

 ings of the related words " inspire " and " ex- 

 pire " are to be changed. Also, what becomes 

 of the " organs of respiration " ? Do they 

 disappear? Or are we to add to lungs, gills, 

 stomata, etc., such structures as root hairs, 

 kidneys, the intestine or other organs that may 

 be concerned with those exchanges between 

 the organism and its surroundings by which 

 the disruptive process is maintained? 



" Eespiration," as it has long been under- 

 stood, is a useful, indeed a necessary, term; 

 the new conception of the energy-releasing 

 processes within the cell deserves to be digni- 

 fied by a new word. The confusion that once 



