41 6 THE WONDER OF LIFE 



for several days, prospecting. They examine the ' rookery ' 

 and go off to sea again, returning in reinforced numbers. 

 Each male chooses a spot — some thirty yards square — ^for 

 his future harem, and jealously guards it against intruders. 

 About two months later the females, who are not nearly so 

 large as the males, appear on the scene, and there is great 

 competition for them, each ' polygamous sultan ' trying 

 to secure from fifteen to twenty wives. Accounts differ a 

 good deal as to the degree of ' give and take ' among rival 

 males. The cubs are born a few days after the arrival of the 

 mothers, and seem to require a good deal of education. 

 Soon after the birth of the young, Professor D'Arcy 

 Thompson tells us, ' the comparative quiet of the rookery 

 is exchanged for a babel of noise and incessant quarrelling.' 

 The old males try to add to the score or so of wives they 

 have apiece ; the wifeless younger males try to secure 

 mates ; there are great fights among rival bullies. ' So 

 all day long the noise of battle rolls along the beaches 

 by the wintry sea, and the growhng and the snaihng, 

 the confusion and the din, are for some weeks together 

 indescribable '. The younger males, or bachelors, herd apart 

 from the others, and both they and the married females 

 go down to the sea to feed. It is noteworthy, on the 

 other hand, that ' the old males starve rather than leave 

 their posts ; they come fat and vigorous in springtime, 

 and are gaunt, emaciated, and scarred with the scars of 

 many battles before they leave again in autumn '. 



Fragrance. — In many butterflies, such as the green- 

 veined white (Ganoris napi), the males have a distinct 

 flowery perfume, which is associated with remarkable 

 ' plume scales ' on the upper surface of the wings. It is 

 readily perceptible if we rub the wings with a camel-hair 



