THE STUDY OF BIOLOGY. 27 



structure, we should also discover that the young kangaroo is born in 

 an immature condition, that it is thereafter transferred to the pouch of 

 its mother, and that it exists therein for many days after birth, being 

 duly nourished by the secretion of the milk-glands which open into 

 the pouch. We might also note that the kangaroos, as every visitor 

 to the Zoological Gardens knows, possess hind limbs which are de- 

 veloped out of all proportion to the fore-legs. In its resting posture, 

 it sits upon a kind of tripod, or three-legged stool, formed by the tail 

 and two hind limbs; and when the skeleton of the hind limb is 

 examined, we find, further, that the great apparent length of the foot 

 is in reality due to the elongation of the animal's instep bones. The 

 foot, we may lastly note, possesses four toes, whereof one (the fourth 

 toe) is very large and conspicuous. The fifth toe is smaller than the 

 fourth ; and the remaining two (placed to the inner side of the other 

 toes) are very small, and united together by a fold of skin. There 

 is no first or great toe in the kangaroo ; and the two large toes form- 

 ing the bulk of the animal's foot are the fourth and fifth toes : the 

 two small and rudimentary toes corresponding to the second and 

 third toes in ourselves. 



Thus much a brief study of " anatomy " would teach us about 

 the kangaroo. Of its development, nothing need be said beyond 

 noting the fact that it is formed and fashioned after the manner, firstly, 

 of all Vertebrates in general, and, secondly, of all other quadrupeds in 

 particular. Kangaroo-development stops short, so to speak, at a 

 lower level than the development of such an animal as a dog, and at 

 a considerably lower level than that of an ape or a man. But, if any 

 proof of the exact nature of the kangaroo were wanting, such facts as 

 those elucidated by its development would at once and indisputably 

 settle its relationship to ourselves, as a low member of our own great 

 class. 



Next as to its "classification." What, it maybe asked, is the kan- 

 garoo's place in nature ? As the claims of structure settled the place 

 and position of whale and fish in the animal series, so the morphology 

 of the kangaroo allocates to it a situation in the quadruped class. 

 The structure of many other animals is found to present a striking 

 likeness to that of the kangaroo. The opossums, the wombats, 

 the native "bears" and "hyenas" of Australian colonists, the 

 kangaroo rats, the phalangers, the bandicoots, and allied forms all, 

 with the exception of the opossums, confined to the Australian 

 province exhibit evident affinities to kangaroo structure. Relying 

 upon structure and development would be found to strengthen 

 the evidence of morphology we should place these animals along 

 with the kangaroo in a special order of quadrupeds to which we give 

 the name of Marsupials, or " pouched " animals. These animals 

 would agree with the kangaroo not merely in lowness of brain 



