CONCERNING EGGS 59 



the greater part consists of yolk, only a small 

 portion of which is utilised in the formation of the 

 embryo, the remainder serving as food for the 

 young when they are hatched. 



The mother nurses her babies in the usual 

 mammalian manner, but as she does not possess 

 any external nipples, her milk is discharged from 

 her glands through numerous small pores that 

 are arranged in a cup-like cavity or depression 

 situated upon her body. 



The adult animals feed upon various forms of 

 insect life, water-snails, shell-fish and worms, 

 for which they probe amidst the mud and 

 sand. 



The food, which is collected under water, is 

 stored in cheek pouches which are situated one 

 on either side of the mouth, the creatures rising 

 to the surface in order to devour the repast at 

 leisure. 



Chiefly aquatic in habits, the platypus is an 

 expert both at diving and swimming. On land, 

 however, its movements are somewhat ungainly, 

 although it is stated to be able to cover the ground 

 at a fair pace. 



The egg-la3dng mammals known as the echidnas 

 are easily distinguished from the platypus owing 

 to the upper part of their heads and bodies being 

 covered with sharp spines interspersed with wiry 

 hairs. 



Their snouts are very narrow and beak-Uke, and 

 their feet are furnished with large and powerful 

 claws — those upon the hind feet being very 



