90 INTRODUCTION. 



Order 15. Insectivora Ex. Moles (Talpidse), Shrew-mice (Sori- 

 cidae), Hedgehogs (Erinaceidae). 



Order 16. Quadrumana. Ex. Aye-aye (Cheiromys), Lemurs (Le- 

 muridae), Spider-monkeys (Ateles), Howlers (My- 

 cetes), Macaques (Macacus), Baboons (Cynocephalus), 

 Gibbons (Hylobates), Orang (Simia), Gorilla and 

 Chimpanzee (Troglodytes). 



Order 17. Bimana. Man (Homo Sapiens). 



GENERAL SUCCESSION AND PROGRESSION OF ORGANIC TYPES. 

 Whilst admitting the impossibility of arranging the animal 

 kingdom upon any linear plan, no doubt obtains as to the 

 fact that some of the fundamental " morphological types," or 

 plans upon which animals have been constructed, are higher 

 than others. Every one admits, for example, that the Ver- 

 tebrate type is higher than the Molluscan or the Articulate 

 type, an admission which is not affected by the fact that the 

 highest Molluscs and Articulates are superior in point of 

 organisation to the lowest Vertebrates. In the same way, 

 within the limits of each sub-kingdom, every one admits 

 that some of the groups are higher than others. Every one, 

 for example, would admit that a Mammal is a superior 

 animal to a Fish. It follows from this that a certain 

 general arrangement of the animal kingdom, as a whole, is 

 possible, upon the comparative basis of the morphological 

 type of the sub-kingdoms. Similarly a general and more 

 exact arrangement of the classes and orders of each sub- 

 kingdom may be made by the degree of perfection in which 

 the type of the sub-kingdom is carried out in each. 



No generalisation of Palaeontology seems to stand on a 

 firmer basis than that which asserts that there has been a 

 general succession of organic types, and that the appearance 

 of the lower forms of life has in the main preceded that of 

 the higher forms in point of time. In other words, it is one 

 of the generalisations of Palaeontology that there has not 

 only been a succession, but also a progression, of organic types 

 in proceeding from the earliest fossiliferous deposits up to 

 the present day. Whilst this general law remains, as we 

 believe, unassailable, there are some important considerations 

 which must not be lost sight of. In the first place, it is 



