256 TOWARDS THE HUMAN FORM 



intelligence, however, exists and functions to-day in the very 

 manner we have just indicated in all the social Insects — White 

 Ants, Wasps, Humble-bees, Bees, and Ants, and we must 

 necessarily bow to the facts. Darwin made a masterly study 

 of what we call instinct in birds, where the word designates an 

 assemblage of unconscious and more or less conscious faculties. 

 He demonstrated that in the same group of Birds, Molo- 

 brns, for instance, a kind of American Starling, we can 

 follow all the stages in the development of an instinct identical 

 with that of the Cuckoo which deposits its eggs in the nests of 

 other birds. It is the same with the social insect, and especially 

 in Ants, where we can see the social instinct, the constructive 

 instinct, and the instinct prompting a provision for both larvae 

 and adult, as well as many another, occurring in different 

 species and genera under forms which are easily graded from the 

 most primitive to the most complex manifestations of in- 

 stinctive behaviour. From this we must conclude that in Insects, 

 as in Birds, instincts are not innate, and were not bestowed upon 

 the creature once for all, without possibility of variation, but 

 were gradually perfected in just so much as the insect modified 

 itself, and that this apparent innateness is nothing but heredity. 

 The same gradation of instinct can be observed in Insects which 

 live solitarily. We know that all insects are not equally 

 endowed in this respect. Those which have preserved the 

 primitive forms and mode of development (Archineuroptera, 

 Orthoptera, Hemiptera) have generally remained at the very 

 bottom of the scale so far as instincts are concerned. Insects 

 with crushing mandibles and a complete metamorphosis 

 (Euneuroptera, Coleoptera) are somewhat better endowed 

 without there being any connexion between this fact and their 

 method of evolution, for the Lepidoptera and Diptera are as 

 poorly endowed as the Archineuroptera, whereas the White 

 Ants of the Neuroptera group are almost equal to the most 

 remarkable Hymenoptera. Their social species, it is true, 

 appeared only during the Secondary Epoch. 



In the order of Hymenoptera, both in the solitary and the 

 social forms, the instincts exhibited can be arranged in a 

 definite series and their progressive evolution followed from 

 species to species, be it in connexion with the building of nests, 

 the provisioning of the young, or the manner of killing the prey, 

 right up to the manifestation of those other instincts that have 



