SENSATION AND REACTION 77 



mort) failed to find its mate when deprived of its feathered 

 feelers, though in its normal state it would run from a 

 considerable distance straight towards a female across the 

 floor of a room. 



That many insects are able to discriminate between 

 foods of various composition has been shown by several 

 observers and experimenters, whether the sense by which 

 the differences are appreciated be defined as taste or smell. 

 Mclndoo (19 1 6) describes the result of mixing various 

 substances with honey or candy offered as food to bees. 

 Wliile as many as 35 or 40 out of a hundred bees ate the 

 pure sweetmeat, none would take candy to which oil of 

 peppermint or carbolic acid had been added, though 22 per 

 cent, partook of honey contaminated with whisky and 

 29 per cent, were attracted by cane sugar with a small 

 amount of cider vinegar. When the bees were offered the 

 alternatives of pure cane sugar, cane sugar and quinine, or 

 cane sugar and strychnine, 47 per cent, ate the first, nearly 

 6 per cent, the second, and 4*6 per cent, the third ; but 

 when the only alternative was between the sugar treated 

 either with quinine or strychnine, 49 per cent, showed 

 preference for the quinine flavour while only 4 per cent, 

 would take the strychnine. The experimenter was espe- 

 cially impressed by this last result, as he failed himself to 

 distinguish by tasting between quinine and strychnine. 

 Pure cane sugar was markedly preferred to sugar containing 

 various salts of sodium and potassium. No bees would 

 eat sugar and potassium cyanide, but sugar and potassium 

 ferrocyanide attracted 33 out of a hundred bees to whom 

 nothing else was offered to eat. 



Reference has been made to the precision of movement 

 which most insects display whether they creep, walk, run, 

 or fly, and observers of their movements have often inferred 

 that they possess some kind of sense of direction. In many 

 cases the adjustment of motion to direction may be most 

 reasonably supposed to work through vision, but many 

 facts suggest that insects possess a definite equilibrating 

 sense analogous to that which is associated with the semi- 



