ME. G. LEWIS OK JAPAKESE LAISTGUBIID^. 351 



natural to look upon these forms in all the large sections of Coleo- 

 ptera as the result of the complex agencies which must arise in, 

 and are inseparable from, compound evolution. But in the 

 ojDening life of a young group greater simplicity is, on the other 

 hand, equally to be expected. Where we observe great diversity 

 of form, there we see equal diversity of habit, as in the Carabidse 

 and Histeridae ; but at present we see neither one nor the other 

 in the Languriidge. 



In a Guciijits the larva and pupa are flat, like the imago ; the 

 first and second stages are entirely passed under bark, and the 

 third stage also in the greatest part. In Gastrolina above 

 noted, a genus which stands next to Ghrysomela, the larvse and 

 pupae are of the ordinary gibbous form of the family, and feed on, 

 in the first stage, and are suspended to, in the second, walnut- 

 leaves. It is not until the imago appears that the insect hflat, 

 and in condition to join the Guciojus and winter under the bark 

 of the Flanera. Even a gravid female could not hybernate under 

 the close-fitting bark ; but copulation takes place on the fresh 

 foliage of spring after hybernation. Here is a singular fitting of 

 a species for special environment during one stage ; but it is only 

 conspicuous to a Coleopterist, because it is unusual in the leaf- 

 eating family of Chrysomelidae. The phenomenon, however, pre- 

 vails throughout the whole of the Lepidoptera and other orders, 

 but, being general in them, attracts less attention. 



As far as the Languriidse are concerned, we can believe that, if 

 they are all reared within a stem, or any enclosure of like capacity, 

 as Prof. Comstock's observations may lead us to suppose probable, 

 it will account for their acquiring the elongate form, which is at 

 present the only form known to us in the family, and of their 

 retaining it. If they should eventually prove, as a group, to be 

 so constantly and invariably elongate as our museums, with 

 slight exceptions, at present exhibit them, they must be either a 

 recent divergence and undifi'erentiated, or the elongate form, 

 when once acquired, answers the requirements of the insect's 

 life better than any other shape, and has been acquired in a fairly 

 simple life, which form inactivity and sluggishness of habit has 

 confirmed rather than modified. 



lu the Heteromera there are analogous forms, both to the 

 Languriidse {DolicTioderus is like Fatua) and to the Erotylidse 

 (Acropteron), and this is the case in many other groups ; so that 

 we cannot say that there_ is any special modification in any one 



