180 SIE J. LUBBOCK ON ANTS, BEES, AND WASPS. 



might be an organ which, having fallen out of use, had become 

 atrophied. M. Dewitz adopts the former view. He concludes 

 that the rudimentary sting of the Formicidse is not a stunted and 

 evanescent organ, but one which has remained in the lowest stage 

 of development, from which the more perfect sting has originated — 

 that we have to do not with a reduced, but with a primitive organ. 

 Any opinion expressed by M. Dewitz on such a subject is, of 

 course, entitled to much weight ; nevertheless there are some 

 general considerations which seem to me conclusive against his 

 view. If the sting of Formica represents a hitherto undeveloped 

 organ, then the original ant was stingless, and the present stiugs 

 of the aculeate ants have an origin independent of that belonging 

 to the other aculeate Hymenoptera, such as bees and wasps. 

 These organs, however, are so complex, and at the same time so 

 similarly constituted, that they must surely have a common origin. 

 Whether the present sting is derived from a leaf-cutting instru- 

 ment, such as that from which the sawfly takes its name, I will 

 at present express no opinion. M. Dewitz would surely not 

 regard the rudimentary traces of wings in the larvae of ants as 

 undeveloped organs ; why, then, should he adopt this view with 

 reference to the rudimentary sting ? On the whole I must regard 

 the ancestral ant as having been aculeate, and consider that the 

 rudimentary condition of the sting of Formica is due to atrophy, 

 perhaps through disuse. 



On the Arrangement of their Nests. 



I have given the following figure (fig. 5), which represents a 

 typical nest belonging to Lasius niger, because it seems to show 

 some ideas of strategy. The nest is between two plates of glass, 

 the outer border is a framework of wood, and the darker colour 

 represents garden mould, which the ants have themselves exca- 

 vated, as shown in the figure. For the narrow doorway («), indeed, 

 I am myself responsible. I generally made the doorways of my 

 nests narrow, so as to check evaporation and keep the nests from 

 becoming too dry. It will be observed, however, that behind 

 the vestibule (b) the entrance contracts, still further protected by 

 a pillar of earth, which leaves on either side a narrow passage 

 which a single ant could easily guard, or which might be quickly 

 blocked up. Behind this is an irregular vestibule (c), contracted 

 again behind into a narrow passage, which is followed by another, 

 this latter opening into the main chamber d. In this chamber 



