opinion maintained in an anonymous letter from Freyberg, published 

 in the 4th volume of Mr. Nicholson's Journal, are sufficient to di- 

 minish in any degree the value of that assistance which mineralogy 

 derives from chemical investigation. 



Description of the Anatomy of the Ornithorhynchus Hystrix. By 

 Everard Home, Esq. F.R.S. Read June 3, 1802. [PAz7. Trans. 

 1802,;?. 348.] 



The specimen from which this description was taken, and which 

 was exhibited to the Society at their Meeting, was brought from 

 New South Wales. It is a male, probably arrived at its full growth. 

 It is seventeen inches in length from the point of the bill to the ex- 

 tremity of the tail ; and its greatest circumference measures likewise 

 about seventeen inches. Its back and sides are covered with quills, 

 the longest of which are about two inches and a half in length. Its 

 bill projects from the head one inch and three-fourths, tapering from 

 its base, where it is seven-eighths of an inch in diameter to its point, 

 where its diameter is not above three-eighths of an inch. It is tubular, 

 convex on the upper, and flat on the lower surface. The tongue is 

 cylindrical, very small towards the point, and eight inches long. This 

 species has a peculiarity in its mode of managing its food, which di- 

 stinguishes it from the Paradoxus. The food is first bruised by small 

 horny prominences adhering to the tongue and palate, and then swal- 

 lowed with a certain quantity of sand, the stomach being sufficiently 

 large to contain this extraneous matter, together with the food, and 

 effectually defended from injury by a cuticular lining. 



Mr. Home proceeds, with his usual accuracy and minuteness, in 

 his technical description, both of the external and internal parts, 

 which he illustrates with a number of figures. Having completed 

 this detail, he observes in general, that this species of Ornithorhyn- 

 chus being a nearer approach to the more perfect quadruped than the 

 Paradoxus, and its tongue being in some respects similar to those of 

 the Manis and Myrmecophaga, he thought it necessary to look among 

 the different species of these genera for other parts of resemblance. 

 The result of this comparison is, that the Ornithorhynchus is essen- 

 tially different from all other quadrupeds, bearing in some respects a 

 resemblance to birds, and in others to the Amphibia, so that it may 

 be considered as an intermediate link between the classes Mammalia, 

 Aves, and Amphibia. To the first class it no doubt approaches nearest 

 in the instance of the Myrmecophaga ; and to the birds it bears a 

 singular affinity in the male organs of generation, as is here illus- 

 trated by comparing its penis with that of the drake. 



From the whole of this investigation are deduced the following 

 characters as peculiar to this animal, considered as a genus. The 

 male has a spur on the two hind legs, close to the heel. The female 

 has no nipples, differing essentially in this, as well as in the organs 

 of generation, from the Mammalia. The beak is smooth, while the 

 rest of the animal is covered with hair. The tongue has horny pro- 



