LIFE, IN ITS HIGHER FORMS. 
>m the high development of the placental Mammalia, 
d an approach to that of the oviparous Vertebrata in 
,encral, and to that of the Reptilia in particular. 
This affinity with Reptiles is most marked in two very 
singular little animals, the Echidna and the Ornithorhynchus. 
They are the lowest forms of Mammalia, displaying some 
points of similarity to Birds, but more to the Lizards, 
especially in the structure of the sternum or breast-hone, 
of the shoulder, and of the limbs generally. The latter in 
particular, known as the Duck-bill, caused no little 
astonishment and even suspicion, among zoologists, when 
the first specimens were sent from New Holland to 
Europe. Here was a four-legged animal, covered with 
hair, but having the feet webbed like a water-fowl, and 
furnished with a beak closely resembling that of a duck ! 
For a long time it was believed that the reproduction of 
this most anomalous crcaturo was by means of eggs ■ but 
it is now ascertained to produce living young, which are 
suckled like those of other quadrupeds. Mr G. Bennet 
has described, in a very interesting Memoir,* the habits 
of life of these curious creatures. 
Few as are the members composing this Sub-class, they 
include what we may consider as the parallels or represen- 
tatives of most of the Orders of the typical Mammalia. 
Thus the Opossums, in their opposible thumbs, seem to re- 
present the Monkeys, the little Myrmecohm the Shrews, 
and the Kangaroos the Ruminants; while more strongly 
drawn analogies exist between the Dasyuri (the “Zebra- 
wolf,” “ Native-devil,” &c., of the Australian colonist) and 
the Carnivora, between the Phalcmgistce and Petauri, and 
* “Trans. afZooI. Soc.,” vol. i. p. 229. 
