DISTRIBUTE INSECT VAUIETY. 293 



Coleoptera, as Lepidoptera, produce variety by approximation or 

 differentiation of the sexes. Like Lepidoptera also, the brightly- 

 coloured sorts vary by an increase o£ the dark or bright pigment 

 and confluence of elytral spots, as has been observed of Bromins 

 qiiadrimaculatus and Panagceus quadripustiilatus. Lastly, in 

 Carabus convexus, Fab., the lines or stria3 on the elytra of some 

 varieties become irregular, and in others they are replaced by 

 punctures, as is also the case in the brown variety of another 

 Carabus, C. cantenidatm. The punctures themselves are likewise 

 liable to be obsolete or supplementary. 



With regard to the Bugs, or Hemiptera, Dr. Puton found that 

 the Plintliism mimUissimus, one of the Lygmche, in the south of 

 France, where it lives in society with ants, had rudimentary 

 elytra and wings ; but in Algiers its elytra were fully developed. 

 This local alar expansion, allowing the species to fly and migrate, 

 is characteristic of the genus ; and Mr. Douglas remarks it is 

 accompanied with a development of the thoracic muscles that 

 changes the corporeal forms from oblong to oval.* Corens 

 spiniger is said to be less in size at Naples than in Calabria, 

 and another bug, Neides tipularius, is stated to be a form of N. 

 parallelm with abbreviated wings. We may find seasonal variety 

 likewise in a common gamboller over pond- water, Hi/drometra 

 lacustris, Fab. ; those individuals, which jerk about and disport 

 themselves in the spring, being reputed apterous — a circum- 

 stance M. Audouin surmises is due to the rigours of winter 

 having cheeked their development. 



* Orthoptera, in their hordes of ravine and rapacity, are so 

 chameleon-like in their changes, even on the same confined spots, 

 that we find their recognition and definition extremely difficult, and 

 still more difficult is it to classify and deduce the operating laws 

 that rule their confused forms and colours. Still, as far as would 

 appear, they betray a general distribution and diversification 

 similar to what may be observed among Lepidoptera. On the 

 Palaearetic area, which has been most worked, we notice species 

 that spread northward from the genial shores of Southern Europe 

 decrease in size, in alar expansion, and in richness of colour ; 

 and one large pinkish-winged grasshopper, Caloptenus italicus, 



* J. W. Douglas, Ent. Mon. Mag., Vol. XVI., pp. 217-219, quotes Dr. Puton 

 to the effect that pilosity is seen in northern and dwarf forms. 



