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on the same plant there is, on the contrary, some slight difference, but, on the 

 other hand, both pupae, though in colour and shape very peculiar, are not 

 distinguishable from each other. Though no special examples of this case 

 have come under my notice, I have therefore no difficulty in accepting that 

 where the larvae are alread changed, the imagines may nevertheless have 

 remained unaltered, and so much the less as we also know, forsooth, that the 

 colour-dimorphism that appears in many larvae, leaves the imagines unaltered. 

 Hence me might assume that through the change of food a differentiation had 

 been caused, which from one primitive species,— either that of Acronvcta Psi, 

 L. or A. Tridens W. V.— has made two, but which has as yet only modified 

 the larval form of the differentiated species, though it has also undoubtedly 

 occurred in the imago, although not yet in an externally visible way, so that 

 the imago of each species now only produces its own larval form. I do not 

 know whether a sufficient study has been made of the ontogeny of the two 

 European species, from which I might learn in what way the first stages of 

 the said larvae differ from each other, and if I might draw some illustrations 

 for this point from it. Such a study, therefore, may well be recommended to 

 the European larvae-breeders. 



Some larvae of Hesperidae, that live in a case-like leaf, have the peculiar 

 custom to shoot their dry excrementa through that case far away as if they 

 were bullets coming from the mouth of a fire-arm. Evidently a phenomenon 

 of cleanliness ; there are more larvae that have the same peculiarity, those for 

 instance, that when pupating evidently intentionally remove their stripped off 

 skins. Others on the contrary, apparently have no objection to live continually 

 surrounded by their excrementa; some even spin it into the cocoon in which 

 they wrap themselves as pupae. 



Some give a remarkable proof of intellectual faculties. Instinct, the admirers 

 of the hollow phrase will say. The real biologist, however, as I have amply 

 explained in my latest work on Mimicry, must know that the psychical nature of 

 living beings is as much in a state of evolution as the physical, and can be 

 observed as such in different stages of development. What people call instinct, 

 without being able to give a further definition of it, is nothing else than such 

 a stage itself, occurring again in many degrees of development; reflex action 

 is a manifestation of a still lower stage and hence the explanation, though not 

 entirely understood yet, given by Romanes of instinct as reflex action into 

 which is imported the element of consciousness. With tropism, by means of 

 which some biologists try to explain it, neither instinct nor reflex action has 

 anything to do. A remarkable instance of such an intellectual faculty of larvae 



