508 ANTS. 



the subject is convenient and will be followed in this and the two suc- 

 ceeding chapters, it must be borne in mind that it is very artificial and 

 schematic, as is clear from the fact that the psychical process in 

 animals, the source of its visible activities, is neither a unity nor a 

 multiplicity. Whatever views may be entertained concerning the nature 

 of this proces^ and the best method of studying it, all authors agree 

 in regarding the simple sensory reactions as the basis of any scientific 

 study of behavior and that this should be supported in turn by a mor- 

 phological study of the sense organs. I shall, therefore, follow this 

 course in our study of the ants, referring the reader to Chapter IV 

 for the necessary data on the structure of the sense organs. For 

 many interesting details, which lack of space compels me to omit, the 

 reader must also be referred to the works of the following authors, 

 who have contributed to our knowledge of sensation in ants : Huber 

 (1810), For el (1874, 1878^ 1886, 1900-01), Lubbock (1881), Bethe 

 (1898, 1900, 1902), Janet (18936, 18941, Wasmann (1899(7), von 

 Buttel-Reepen (1900), Miss Fielde (19010, 19016, 1902, 19030, 19036, 

 1904, 1905), Miss Fielde and Parker (1904), Yiehmeyer (1900), 

 Pieron (1904, 1905, 1906, 1907), and Turner ( 19076). 



The study of the sensory responses of ants is beset with grave 

 difficulties, first, because these responses are more numerous, complex 

 and obscure than in many lower animals ; second, because several senses 

 may be coimplicated in what appears as a single response, and third, 

 because the sense organs of ants are merely analogous and by no means 

 homologous with our own. These conditions prevent the observer and 

 experimenter from isolating a single sense. Both the structure of the 

 sense organs and experiment show, moreover, that ants respond to 

 stimuli to which our own senses are irresponsive. It has, therefore, 

 been suggested by Bethe and others that we abandon the terminology 

 of human sensation with its subjective connotations and adopt a new 

 one of purely objective import, that we speak of photorecepting instead 

 of seeing, chemorecepting instead of smelling, tasting, etc. The 

 reasons given for adopting these terms are not very cogent. Strictly- 

 speaking, we should have to use them for the higher animals and our 

 fellow-men. As Forel remarks: "One ought not to say, 'My wife 

 has a headache.' One should say, ' This animal machine which I 

 believe to be my wife exhibits certain facial cortortions and emits 

 certain articulate sounds that correspond with those emitted by myself 

 when I have a headache, but I have no right to say that she has a 

 headache.' ' The difficulties above mentioned are not to be avoided 

 by adopting a new nomenclature, but by further and more persistent 



