EESPIEATOEY ORGANS. 77 



lateral clu corps cle I'msecte, en passant en dessous cle 

 la principale tracliee."^ 



" Tel est I'aspect," lie concludes, " sous lequel se 

 presente le systeme traclieen des Podurelles," a term 

 by which he denotes all the Collembola. 



He appears, therefore, to consider the description as 

 applicable to the whole group ; and his statement has 

 been so understood by succeeding writers, as, for 

 instance, by Yon Siebold," and Gervais.^ 



I have not had an opportunity of examining A. 

 similata, the species which he appears to have princi- 

 pally studied with reference to the respiratory organs, 

 and cannot, therefore, call in question the correctness 

 of Nicolet's description as regards that species, but 

 his statements certainly do not aj^ply to the Podnridce 

 generally, in none of which do I believe that any such 

 system exists. 



In this view I am confirmed by Meinert, who says, 

 " I look upon the statements of Nicolet and of Von 

 Olfers as entirely erroneous, and so far I agree with 

 Lubbock." ■ 



Smynthurus, on the contrary, has a well-developed 

 system of trachese (PI. LXII, figs. 8 and 9). There 

 are, however, only two large spiracles ; at least I was 

 unable to see any others ; and all the larger trachea35 

 even those in the posterior part of the body, seemed 

 to me to be traceable up to them. It is very 

 unusual for an articulate animal to have only two 

 spiracles ; and their position is still more extraordi- 

 nary, for they open on the underside of the head, 

 immediately below the antenna). I know no insect 

 which has spiracles either in the head or between it 

 and the prothorax, and Burmeister (' Handbook of 

 Entomology,' p. 165) even goes so far as to state 

 that none are ever so situated. It appears, however 



' Nicolet, ' Reclierclies p. s. a I'Histoire des Podurelles,' p. 49. 

 " ' Auatouiy of the Invertebruta,' translated by Burnett, p. 438 ; and 

 also 'Lehrbuch der vergieicbenden Anatomie,' p. 620 . 

 3 'Insectes Apteres,' vol. iii, p. 385. 



