METHODS OF COLLECTING AXD STi'DYlXG AXTS. 549 



joints, the ommatidia and teeth of the mandibles, it 'will be found neces- 

 sary to use a compound microscope. 



I am convinced that there is no form of entomological work more 

 fascinating than collecting ants, for these insects are everywhere abun- 

 dant and no two of their colonies ever present the same picture to the 

 observer. Hence one is always coming upon new and interesting facts 

 in the commonest species, and even in localities in which one has been 

 diligently collecting for years. Certainly there is no more delightful 

 avocation for the man who desires a not too strenuous employment 

 that will keep him in the open air. Many years ago Moggridge called 

 attention to the value of myrmecology to the valetudinarian and the 

 convalescent, and it is surprising that physicians have so seldom rec- 

 ommended it to patients who need to spend much time out of doors 

 and to have some intellectual interest that will make this seem worth 

 while. 



Although field study is absolutely essential to an understanding of 

 the taxonomy and ethology of ants, it must be supplemented by obser- 

 vations on colonies kept in artificial nests. And while such colonies 

 are necessarily prevented from manifesting all their instincts in a per- 

 fectly normal manner, this disadvantage is more than outweighed by 

 the great ease and thoroughness with which nearly all of their activities 

 can be observed. Artificial nests must, in fact, be used in all studies 

 on the relations of myrmecophiles to their hosts and the behavior of 

 ants towards their young. 



Various artificial nests have been devised, but these are all of two 

 types those with and those without earth. Ants kept in nests of the 

 former type are, of course, removed from one of the most important 

 elements of their natural environment. Nevertheless, this does not 

 interfere with their other activities ; the excavating instinct simply 

 remains in abeyance without inconveniencing the insects. Naturally, 

 the nests containing earth were the first to be devised and the conclu- 

 sion that this substance can be dispensed with is of comparatively 



V 



recent date. 



The earliest account of an artificial nest I have seen is in Swammer- 

 dam's " Biblia Naturae." This remarkable entomologist placed the ants 

 in a quantity of earth in a flat dish and surrounded this with a strip 

 of wax, which was five fingers broad, hollowed out and filled with 

 water. This served as a moat and prevented the ants from escaping. 

 A modification of Swammerdam's nest has been recently recommended 

 and will often prove to be useful when it is necessary to construct a 

 nest on very short notice. It consists of a dish containing some earth 

 covered with a pane of glass and set in a larger dish containing water. 



