360 



NEUROPTERA 



Termites is imperfect, and refers, moreover, to different species ; 

 it would appear that considerable diversity exists in many 

 respects, but on this point it would be premature to generalise. 

 What we know as to the respiratory system is chiefly due to 

 F. Miiller. 1 The number of spiracles is ten ; Hagen says three 

 thoracic and seven abdominal, Miiller two thoracic and eight 

 abdominal. In fertile queens there usually exist only six 

 abdominal stigmata. There is good reason for supposing that 

 the respiratory system undergoes much change correlative with 

 the development of the individual ; it has been suggested that 

 the supply of tracheae to the sexual organs is deficient where 

 there is arrest of development of the latter. 



The alimentary canal is only of moderate length. Salivary 

 glands exist, as also do salivary reservoirs ; these latter are large, 



in some species remarkably so. The 

 oesophagus is slender, but abruptly 

 enlarged behind to form a large crop ; 

 a proventriculus is apparently either 

 present or absent ; the chylific ventricle, 

 or stomach, is slender and simple. The 

 Malpighian tubules are very long ; their 

 number is probably from four to eight 

 in the adult, and in the earlier stages 

 less. Behind the tubes the alimentary 

 canal forms a large paunch, and after 

 this there is a small intestine and 

 rectum. The paunch is a peculiar 

 structure, and probably of great import- 

 ance in the economy of Termites. 



These creatures emit minute quanti- 

 of a secretion that is corrosive, and 



FIG. 229.-Head and alimentary 



canal of Term.es lutifugus can act on metal and even glass ; 2 its 



(nymph). , head ; b, salivary , i j 



glands ; c, salivary receptacles ; nature and source are not understood. 

 d, crop ; e, stomach ; /, intes- Hagen describes peculiar structures in 



tiual paunch; g, small, h, v v v f J 1 



large intestine ; i, Malpighian the rectum to which lie IS inclined a 



tubes ; *, extremity of body.. to ascr ibe the origin of this substance, 



(After Dufour.) 



but this is very uncertain. 

 The brain is small ; the infra-oesophageal ganglion is placed 



1 Jena. Zcitschr. Naturw. ix. 1875, p. 257. 

 2 Bidie, in Nature, xxvi. 1882, p. 549. 3 Linnaea Entomologica, xii. 1858, p. 305. 



