66 MAMMALIAX DESCENT. [Lect. III. 



always some losses by drowning, until the sheep learn 

 the meaning of those dark waters. 



The earth has often had her shakino; fits and her 

 attacks of colic, and then the living creatures suffer 

 with their mother ; those that escape are the strongest 

 or the most cunning ; those that can " rough " it in new 

 homes, or that are deftest in escaping from danger. 

 Nature has, unconsciously, adopted this rough method 

 of culling out her weaker tribes — appointing them for 

 slauo'hter — and of saving; the best for the increase of the 

 flock. These sugo'estions relate to the incomino; of the 

 Eutheria, of wJiich I must treat soon ; if Nature had not 

 dispossessed the Metatheria, and placed nobler beasts in 

 their room, we ourselves — the Eutheria of the Eutheria, 

 the noblest of the noble — should have had no existence. 



I now j)ass from that old occupation. Husbandry, 

 to this new work. Embryology ; and if the reader 

 will give me a little attention, I will show him reason 

 for believing that the Marsupial group arose from similar 

 low forms to those that o;ave orioin to us and the nobler 

 beasts, some of which, indeed, may be transformed Mar- 

 supials ; and that the line of demarcation between the 

 nobler and less noble t}^3es does not form a perfect fence. 



In the study of nature, as every one knows, that 

 seems to be the most bewitching ])avt in which each 

 particular observer is working ; the skeletal frame- 

 work takes the precedence T\ith most of us. There are 

 many excellent diagnostic marks in the skeleton of the 



