NOTE-BOOK OF A NATURALIST. 171 



Most true ; but the same Power that willed the birth 

 of the creature in such an embryotic condition has 

 guarded against the possibility of this fatal result. The 

 epiglottis and arjrtenoid cartilages are elongated and ap- 

 proximated, and the slit of the glottis is consequently 

 placed at the apex of a conical larynx, which projects, as 

 in the whales, into the posterior nostrils, where it is 

 closely embraced by the muscles of the soft palate. Thus 

 is the air-passage completely separated from the fauces, 

 and as the mother injects the milk the divided stream 

 passes, without the possibility of its ' going the wrong 

 way,' on each side of the larynx into the oesophagus and 

 stomach.* 



It has been remarked, that the conveyance of the foetus 

 into the pouch is probably effected by the mouth of the 

 mother. The reasons for this belief are well given by. 

 Professor Owen, who observes, that apart from the other 

 circumstantial evidence, this mode of transmission is con- 

 sistent with analogy, the mouth being always employed 

 by the ordinary quadrupeds, — dogs, cats, and mice, for 

 instance, — for the purpose of removing their helpless off- 

 spring. The tender embryo would be more liable to in- 

 jury from the fore-paws; and these, from the absence of 

 a thumb, could not so securely effect the conveyance as 

 the lips, which can be opposed to each other. 



The advantages of such a vivarium as that belonging 

 to the Zoological Society of London, in the Eegent's 

 Park, are here strongly manifested. Professor Owen was 

 enabled by his autopsy to correct the error of Geoffrey 



* Geoffi'oy first described this perfect contrivance ; but, as Pro- 

 fessor Owen obsen^es, John Hunter seems to have foreseen the 

 necessity of it, and, indeed, as the Professor further remarks, there 

 are evidences in Hunter's preparations in the museum of the 

 College, that he had anticipated most of the anatomical discoveries 

 which have subsequently been made upon the embryo of the 

 kanguroo. 



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