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111, On the Anatomy of Ants. By Sir John Lubbock, Bart, MB F.B S F.L S 

 B.CL LL.B Vice- Chancellor of the University of London, President of 'the 

 Entomological Society. J 



(Plates XI. & XII.) 



Bead February 6th, 1879. 



Introductory Bemarks. 



IN conjunction with the observations on the habits of Ants, which the Society has done 



me the honour of publishing from time to time in the Journal, I have also been studying 



their anatomy especially with reference to the muscular system. Of the anatomy of the 



Society '1877* **** ^ ^^^ ™ ^ ' Tnm8action8 of the Microscopical 



The present paper is devoted to the thorax, with special reference to Basins favus. 

 Though it is founded on numerous dissections, and on more than 1000 sections beautifully 

 prepared for me by Mr. Newton, of the School of Mines, and Mr. Robertson, of Oxford it 

 is still very imperfect ; and I am only induced to bring it before the Society in its present 

 incomplete state because, while I hope it will be found to add somewhat to our knowledge 

 I see little prospect of being able to work out the subject as thoroughly as I could wish ' 

 As a general rule, the thorax of insects is considered to consist of three more or less 

 well-marked segments, usually known by the names suggested by Nitzsch-prothorax 

 mesothorax, and metathorax. r ' 



Dr. Ratzeburg, however, published in 1832 a memoir (< Ueber Entwickelung der fuss- 

 losen Hymenopteren-Larven, mit besondercr Riicksicht auf die Gattung Formica ') in 

 which he maintained that the fifth segment of the larva forms, not the so-called « scale >' 

 or firstabdommal segment, but the hinder part of the thorax. This view has also been 

 maintained by Audouin and Latreille; while, on the contrary, others, as, for instance, 

 Kirby and Spence and MacLeay, consider the thorax of these insects to be composed 

 ot three segments, as usual. 



Burmeister, indeed, roundly observes (< Manual of Entomology,' Shuckard's transl. 

 p. b5J that Audouin s assertion is unfounded. 



Lepelletier cle St.-Fargeau, in his < Histoire Naturelie des Hvmenopteres ' (183G) 

 expresses the same opinion. « II me parait," he says, "plus simple parler comme voient 



7? y6 T • n, m n alS °' ^ MS eXCdlent ' Introd ^ tio » to the Modern Classification 



of Insects (1810, p. 227), adopts the same view. It may, he admits, « be asserted that, 

 as the body of the imago possesses two or three segments fewer than exist in the body of 

 larva, we may suppose that the loss of one of these segments takes place at least in this 

 manner, and in this part of the body. This, however, can only be done by admitting that 

 the head and three thoracic segments of the imago are composed of five larvta-se.- 

 ments instead of four, an admission negatived by all analogy with pedate larva,." 



* See Quekett Lecture, Monthly Microscopical Journal (1877). vol. xviii. p. 121. 



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