SUCCESSION OF REPRESENTATION CONSTANT. 75 



processes) is, to show that the genus Polydr/rus represents 

 the Nipnplialides, or scolopendriform butterflies. Another 

 iuliform larva has the body terminated by two little 

 points, thereby denoting its representation of the thysa- 

 nuriform caterpillars. Thus every natural group, not 

 only of the diurnal butterflies, but — so far as we yet 

 Jjnow — of the whole order Lepidoptera, contains repre- 

 sentations of the primary forms of larvse, following each 

 other in a uniform series, and producing perfect insects 

 whose structure harmonises with this theory. Where 

 natural groups are comparatively small, and pre-emi- 

 nently typical, it sometimes occurs that all the larvie are 

 uniform, without any of the above modifications. We 

 see a strong instance of this in the old genus Pieris, the 

 most typical, according to our views, of all annulose 

 animals. It is to this very circumstance we must attribute 

 the fact of all the Pierian larvae being iuliform. But, 

 when groups are very extensive, we consequently find a 

 greater variety of shape, of colour, and even of struc- 

 ture, in the perfect insects ; and this extends also to their 

 larvffi. The genus PapUis of Latreille, the very next 

 after that of his Pieris, is a case in point. We ventured, 

 some years ago, to break up this most natural group into 

 minor subdivisions, because we found it contained iuli- 

 form, scolopendriform, thysanuriform, vermiform, and 

 anopluriform larvae, while the perfect insects produced 

 from them imitated, in some way or other, each of the 

 great divisions of the lepidopterous circle. 



(JoQ.) In orders where the metamorphosis is imper- 

 fect or incomplete, and the larvae more or less represent 

 the perfect insect, the analogies we have already detailed 

 can nevertheless be traced. Thus, while the lepidopterous 

 caterpillars live upon vegetables, the Hemiptera, in their 

 typical example (^Reduviidcp), are carnivorous: like all 

 the raptorial types, these insects live by rapine, and suck 

 the blood or juices of their victims. The aquatic, or 

 anopluriform, type is seen in the active larvae of the 

 dragon-flies, in the neuropterous order. 



(67.) We shall now briefly notice the shape and 



