[175] In this sense Lubbock says:--“It is evident that creatures which, like the majority of insects, live during the successive periods of their existence in very different circumstances, may undergo considerable changes in their larval organization in consequence of forces acting on them while in that condition; not, indeed, without affecting, _but certainly without affecting to any corresponding extent_, their ultimate form.”--“Origin and Metamorphoses of Insects,” London, 1874, p. 39. [176] “Grundzüge der Zoologie,” 1875. [177] [Lepidopterists are of course aware that even these distinctions are not absolute, as no single character can be named which does not also appear in certain moths. The definition in this case, as in that of most other groups of animals and plants, is only a general one. See, for instance, Westwood’s “Introduction to the Classification of Insects,” vol. ii. pp. 330-332. Also some remarks by C. V. Riley in his “Eighth Annual Report” on the insects of Missouri, 1876, p. 170. With reference to the antennæ as a distinguishing character, see Mr. A. G. Butler’s article in “Science for All,” 1880, part xxvii. p. 65. R.M.] [178] The genus of _Morphinæ, Discophora_, possesses hairs very similar to those of the genus _Cnethocampa_ belonging to the _Bombycidæ_. [179] [The larvæ of genera 14, _Phyciodes_, and 35, _Crenis_, are likewise spiny. See Edwards’ “Butt. of N. Amer.” vol. ii. for figures of the caterpillar of _Phyc. Tharos_: for notes on the larvæ of _Crenis Natalensis_ and _C. Boisduvali_ see a paper by W. D. Gooch, “Entomologist,” vol. xiv. p. 36. The larvæ of genus 55, _Ageronia_, are also spiny. (See Burmeister’s figure of _A. Arethusa_, “Lép. Rép. Arg.” Pl. V. Fig. 4). The larvæ of genus 98, _Aganisthos_, also appear to be somewhat spiny (see Burmeister’s figure of _A. Orion_, _loc. cit._ Pl. V. Fig. 6), and this raises the question as to whether the genus is correctly located in its present position. The larvæ of the following genera figured in Moore’s “Lepidoptera of Ceylon,” parts i. and ii., are all spiny:--6, _Cirrochroa_ (Pl. XXXII.); 7, _Cynthia_ (Pl. XXVI.); 27, _Kallima_ (Pl. XIX.); and 74, _Parthenos_ (Pl. XXIV.). Many species of caterpillars which are spiny when adult appear to be spineless, or only slightly hairy when young. See Edwards’ figures of _Melitæa Phaeton_, _Argynnis Diana_, and _Phyc. Tharos_ (_loc. cit._) and his description of the larva of _Arg. Cybele_, “Canad. Entom.” vol. xii. p. 141. The spiny covering thus appears to be a character acquired at a comparatively recent period in the phyletic development. R.M.]