I have often remarked when riding a nervous horse, that he will invariably become alarmed, and sometimes start at nothing, on arriving at some spot where something had once occurred to frighten him. The sight of the spot brings up the image of the {109} object or sound that startled him; or, to adopt a later interpretation of memory, the past event is reconstructed in his mind. Again, I have noticed with dogs, when one is brought to a spot where on a former occasion he has battled with or captured some animal, or where he has met with some exciting adventure, he shows by a sudden change in his manner, in eyes and twitching nose, that it has all come back to him, and he appears as if looking for its instant repetition. [Sidenote: The lower kind of memory] We see that we possess this lower kind of memory ourselves--that its process is the same in man and dog and squirrel. I am, for instance, riding or walking in a part of the country which all seems unfamiliar, and I have no recollection of ever having passed that way before; but by-and-by I come to some spot where I have had some little adventure, some mishap, tearing my coat or wounding my hand in getting through a barbed-wire fence; or where I had discovered that I had lost something, or left something behind at the inn where I last stayed; or where I had a puncture in my tyre; or where I first saw a rare and beautiful butterfly, or bird, or flower, if I am interested in such things; and the whole scene--the fields and trees and hedges, and farm-house or cottage below--is all as familiar as possible. But it is the scene that brings back the event. The scene was impressed on the mind at the emotional moment, and is instantly recognised, and at the moment of recognition the associated event is remembered. {110} CHAPTER VI Insects in Britain--Meadow ants--The indoor view of insect life--Insects in visible nature--The humming-bird hawk-moth and the parson lepidopterist--Rarity of death's-head moth--Hawk-moth and meadow-pipit--Silver-washed fritillaries on bracken--Flight of the white admiral butterfly--Dragon-flies--Want of English names--A water-keeper on dragon-flies--Moses Harris--Why moths have English names--Origin of the dragon-fly's bad reputation--_Cordulegaster annulatus_--_Calopteryx virgo_--Dragon-flies congregated--Glow-worm--Firefly and glow-worm compared--Variability in light--The insect's attitude when shining--Supposed use of the light--Hornets--A long-remembered sting--The hornet local in England--A splendid insect--Insects on ivy blossoms in autumn.