318 



SCIENCE 



[N. S. Vol. XLIV. No. 1131 



ends with a description of those crustaceans 

 parasitic on fishes to which the name " sea 

 lice " is given. This internal evidence cer- 

 tainly lends itself to the view that the dolphin's 

 louse was a sucking fish. 



In working up the literature, two references 

 of marked interest just here have been found. 

 Hasselquist, the friend and pupil of Linnreus, 

 in his " Reise nach Palsestina " (published in 

 1762) refers to an Echeneis neucrates (an old 

 spelling of naucrates) collected at Alexandria 

 and records that the Arabic fishermen there 

 called it Chamel el Ferrhun. This term Dr. 

 Frank E. Blake, of the Johns Hopkins Uni- 

 versity, very kindly translates for me as the 

 " louse of the terrible one " — i. e., a shark. 



Another like name is to be found in the 

 writings of another eastern traveller, Forskal, 

 likewise a pupil of Linnssus. He collected on 

 a shark at Djidda, a town situated about half 

 way down toward Aden on the eastern shore 

 of the Eed Sea, an Echeneis neucrates which 

 the natives there called Kami el Kersh, and 

 which he translates the " louse of the shark." 

 Dr. Blake kindly writes me that this term is 

 more properly to be rendered " the louse, of 

 the fish of prey" (which Forskal tells us was 

 a Carcharias shark). From all of which we 

 see that in the east, where habits and customs 

 and even names change slowly, the sucking- 

 fish was still called " the louse " some 2,000 

 years after Aristotle. 



"We now come to the most interesting point 

 of all in this discussion, which is that if one 

 reads Aristotle closely he will be convinced 

 that the Father of Natural History never saw 

 the shark-sucker. Aristotle's descriptions of 

 other fishes are very clear, evidencing keen 

 powers of observation, and it is not to be 

 thought that, having ever seen and examined 

 the sucking-fish, he could have failed to give 

 an explicit description of the sucking disk. 

 Note also that his words are "... which some 

 call the Echeneis or ship-holder." He is 

 quoting from some one else and in the judg- 

 ment of the present writer never saw the 

 Echeneis. 



E. W. Gudger 



State Normal College, 

 Greensboro, N. C. 



SPECIAL ARTICLES 



ANTAGONISM AND WEBER'S LAW 



When toxic substances act as antidotes to 

 each other this action is called antagonism. 

 It is usually found that when antagonistic 

 substances are mixed in various combinations 

 there is one proportion which is more favorable 

 than others. If this favorable proportion be 

 maintained it is well known that considerable 

 variation in the concentration of the antago- 

 nistic substances is permissible for many plants. 

 It has been pointed out by the writer 1 that 

 while variations in concentration affect the 

 form of the antagonism curve they do not in 

 general affect the proportions which are most 

 favorable for life processes. 



It is therefore evident that if we wish to 

 preserve the favorable character of a mixture 

 when the concentration of any antagonistic 

 substance is increased we must at the same 

 time increase the concentration of the others 

 in the same proportion. The law of direct 

 proportionality found in such cases is in real- 

 ity Weber's law, as Loeb 2 has pointed out in 

 discussing his experiments on animals. In 

 regard to the significance of this Loeb says : 



Since this law underlies many phenomena of 

 stimulation it appears possible that changes in the 

 concentration of antagonistic ions or salts are the 

 means by which these stimulations are brought 

 about, as suggested by my ion-protein theory and 

 by the investigations of Lasareff. 



In view of the importance of these relations 

 it seems desirable to ascertain, if possible, what 

 mechanism exists which makes one proportion 

 better than others and preserves this pre- 

 eminence in spite of variations in concentra- 

 tion. 



The writer has formulated a theory 3 involv- 

 ing precisely this kind of mechanism. Ac- 

 cording to this theory the electrical resistance 

 and the permeability of protoplasm are deter- 

 mined by a substance M which is formed and 

 decomposed by the reactions 

 A— >M^>B 



Under normal circumstances M is formed as 



^Botanical Gazette, 58, 367, 1914. 



2 Proc. Nat. Acad. Sciences, 1: 439, 1915. 



3 Proc. Am. Phil. Soc, 55, 1916. 



