210 DIVERSIONS OF A NATURALIST 



males than in the females, as is also the case in many 

 other lower animals where smell is a guide to mating. 

 A single female of the vapourer moth, which is common 

 in the London squares and parks, has been found to 

 attract when placed in a box in an open window in 

 Gower Street a number of males from the neighbouring 

 plantations ; and such is the penetrating and powerful 

 character of these odorous substances produced by female 

 moths that in one species, in which the female is wingless 

 and lives under water, the odour escapes through the 

 water and attracts the males in quantities to its surface. 

 The females then arise from the depths, and, like mer- 

 maids or the witch of the Rhine, draw the infatuated 

 males beneath the water to love and death. In several 

 butterflies it has been shown that the males produce 

 sweet perfumes on the surface of the wings, which can 

 be detected as such by man, and act as stimulants to the 

 mate-hunger of the female butterflies, which follow the 

 scented male in numbers. The sense of smell is thus 

 seen to be a much more powerful guide in insects than 

 might be supposed, and it is of equally great importance 

 to them in other enterprises and activities of life besides 

 those of courtship. It has also a leading importance in 

 all the lower and lowermost animals, and is the ultimate 

 guide (for smell and taste are not separable in such 

 simple forms) of the motile spermatic filament in its 

 journey to the egg cell. 



I have in the course of these notes on " Courtship " 

 more than once stated that though man shares in 

 common with all other animals the ultimate impulse to 

 " courtship," namely, " mate-hunger," yet that it would 

 be a mistake to suppose that he has mechanically in- 

 herited from animal ancestors (as they do) those methods 

 of attracting and endeavouring to fascinate the female, 



