138 Zoological Society. 



an inch ; the parie/fs of the smaller pouch were thicker,' and exhibited 

 patches of glands on the inside j its length was half an inch. The 

 terminal orifice of the ilium is in the form of a slit with tumid margins 

 situated on the middle of the ridge which separates the two pouches, 

 and therefore liable to be closed by the lateral pressure of the faecal 

 matter distending those pouches. 



" Should this structure be confirmed by subsequent examinations 

 of other individuals of the six-banded species, the absence of a ccecum 

 can no longer be admitted among the generic characteristics of Dasy- 

 pus. And it is interesting to observe, that the absence or presence 

 of a ccEcum as a generic distinction holds with as little force in the 

 allied genus Myrmecophaga : for according to Daubenton there exist 

 in one species {Myrm. didactyla, Linn.) two small ci:eca ; while the 

 Tamandua (Myrm. Taniandua, Cuv.), we are assured by M. Cuvier, 

 has not any. In these apparently capricious variations of structure 

 among the Edentata, it is impossible not to observe a tendency or an 

 approximation to the structure of another class; which I am inclined 

 to think is that of Birds. For in addition to the double ccecum, a 

 peculiarity so remarkable in that class, we have also a gizzard-like 

 structure exhibited in the tendinous external appearance and thickened 

 muscular coat of the stomachs of the Dasypodce, and a still nearer 

 approximation to that form of stomach in the Manis, where the muscular 

 coat at the pyloric end is 5 lines in thickness, and the inner surface is 

 defended by a strong cuticle, roughened with papiUis . A similar struc- 

 ture exists also in the MyrmecophagcB , which moreover supply the want 

 of grinders in the mouth by swallowing, in the same manner as the 

 Gallinaceous Birds, small pebbles for the purpose of bruising and de- 

 stroying the vitality of the insects which constitute their food. (See 

 Burt in Asiatic Researches, vol. ii. p. 354, with respect to the fact of 

 small stones and gravel being swallowed ; and Lawrence's Blunien- 

 bach, Comp. Anat. 2nd edit. p. 89. for the true physiology of the fact.) 

 In this genus also we find mucous glands about the os hyoides, of the 

 nature of those follicles which in Birds take the place of the conglo- 

 merate salivary glands of the Mammalia, and the secretion of which 

 serves in the Ant-eaters, as in the Woodpeckers, to lubricate a pro- 

 jectile tongue. In another group of the Edentata, viz. the Bradypodce, 

 we are presented with a still more marked affinity to the structure of 

 birds, in the abnormal number of cervical vertebra; exhibited in the 

 three-toed Sloth, a peculiarity which it is difficult to refer to any other 

 circumstance than the disposition of nature to pass by means of this 

 anomalous order from the Mammalia to the Birds. The transition is 

 indeed nearly completed by the Monotremata ; for of the two genera 

 contained in this order. Echidna presents us with the quills, and 

 Ornithorhynchus with the beak, of a bird ; and it is far from being 

 proved that the mode of generation is not the same *. 



December 13. — The Chairman (The Hon. Twiselton Fiennes) 

 exhibited a specimen of a hybrid Duck bred between a male Pintail 

 and a common Duck. It was one of a brood of six, several of which 

 were subsequently confined with the male Pintail from which 



* Seep. 117.— Edit. 



they 



