Lect. II.] RELATION OF MAMMALS TO REPTILES. 5 1 



group. Of coiir.se, the scaly covering is mimetic of the Lizard's 

 scales, and is in reality made up of cemented hairs ; that may 

 pass ; hut not the structure of the sternum in some species, with 

 its long ' xiphisternal horns,' as in the SfeUioiwhe, and the 

 cartilaginous abdominal rihs, as in the Chameleons, and some other 

 kinds."^ In the poverty of the existing, hut highly modified, Proto- 

 theria, we are glad to get any addition to our materials for work, any 

 knowledge that may help us in our deductions. As I shall soon 

 show, the Edentata are only a sort of Eutheria, or high kind of 

 mammal, quoad hoc, in this and tliat point in their organisa- 

 tion ; in other respects they have kept in a Ioav estate, having 

 the slow temper of some races of men, who are haters of change, 

 however beneficial, and of whom it may be said " as their fathers 

 did, so do they." 



My task in writing of these types, after straining the eyes of my 

 mind to see what sort of folk those mammalian forefathers were, is 

 rendered more difficult through my being precluded the free use of 

 technical terms. A rustic gymnast in a sack, with nothing but his 

 homely features free, and yet having the necessity of jumping laid 

 upon him, is not more an ol^ject of sympathy than a biologist, 

 when robbed of his familiar terms — his special nomenclature. 

 As the movements of the one are of necessity a series of jerks, so 

 the thoughts of the other are too often put into language that to an 

 easy-going, Avell-trained writer must seem to be spasmodic. Loosen- 

 ing my bonds a little, however, and taking a few technical liberties 

 with the reader, I Avill endeavour to give some of the remarkable 

 evidences to be found in the quasi reqMlian nature of these prim- 

 ordial beasts. In the mid-region of the Vertebrata, especially 

 amongst the Serpents and Lizards, we come across some very remark- 

 able stnictures in the fore part of the organs of smell ; these are 

 called " Jacobson's organs." They were described by Rathke, in the 

 Snake, under the term "nasal glands"; that term was adopted l)y me 

 in my papers on the Skull of the Snake and of the Lizard.'^ In those 

 papers the contained organ was not described, as not lu'ing in my plan, 



1 See my memoir on the " Slioukler-Girdle and Sttrnuin," Fuoj Socidij 

 Publications, 1868, plate xxii. fig. 13. 



-Philosophical Transactions, 1878, plates xxvii.-xxxiii., outl 1879, plates 

 xxxvii.-xlv. 



