210 THE BOOK OF THE ANIMAL KINGDOM 



parent; while after the extrusion from the egg, the young are 

 nourished by milk secreted by special glands situated within a 

 temporary pouch, into which the head of the young animal is 

 inserted and retained. . . . The milk-glands are of simpler structure 

 than those of other mammals. . . . The skeleton differs from that 

 of the Higher Mammals, and thereby corresponds with that of 

 certain lower Vertebrates, in regard to the structure of the shoulder- 

 girdle, or that portion which serves for the support and attachment 

 of the bones of the fore-limb." 



The nearest allies of the Monotremes among the Vertebrates 

 apparently are a group of Reptiles, whose fossil remains occur in 

 the Secondary Rocks of South Africa. These Anomodonts, as the 

 fossil Reptiles are termed, are, says Lydekker, "the only known 

 vertebrates having a shoulder-girdle of the type characterizing the 

 Monotremes." For many other interesting facts concerning the 

 structure and affinities of the Monotremes, the student is advised 

 to consult Mr. Lydekker's handbook, Marsupials and Monotremes. 



PLATYPUS. The Platypus, or " Duck-Bill" (Fig. 164), as it is 

 often referred to in Australia, is a shy aquatic animal inhabiting 

 rivers and streams of Queensland, New South Wales, Victoria, 

 South Australia and Tasmania. It is not a large animal, the head 

 and body of an adult male measuring eighteen inches, tail six inches. 

 The female is of slightly smaller dimensions. The general colour 

 of the fur on the upper parts of the body is umber or blackish- 

 brown, and on the lower portions greyish-white. The broad, flat 

 bill or beak is encased in sensitive skin, black in colour. The tail 

 is broad and flattened and the feet are webbed. A large horny spine 

 or spur is present on the hind-foot of the male. There has been a 

 great deal of controversy regarding this curious organ, which is 

 connected with a gland which is said to secrete poison. Old bush- 

 men will relate stories of having been "stung" by a Platypus with 

 this spur and suffering dire consequences. How much reliance is 

 to be placed on such statements it is difficult to judge. No proof 

 has yet been given that the Platypus is a "poisonous" animal, and 

 the function of the spur cannot be said to be rightly understood at 

 present. It has been suggested that the horny process is used by 

 the male as a weapon when fighting for the possession of a mate. 



The Platypus is of such a retiring disposition that it is very 

 difficult to observe in a wild state. It spends a great part of its 

 life in the water, and is a splendid swimmer and dives with ease 



