366 Dr. W. Kukentlial on the Orlcjia and 



our gaze to range further afield, should consider the relation 

 of the separate contribution to the great whole, and from these 

 general considerations should derive new ideas, or in some 

 sort form plans, to guide us in our future work. It often 

 happens that these ideas are widely different from that which 

 one day appears as the result of laborious individual investi- 

 gation in the same direction. If, however, we are justly 

 conscious of this diiference, we may well venture to give 

 utterance at some time to such ideas, especially if, as on this 

 annually recurring occasion, we are not in a position always 

 to adduce verified results of our own original work, such as 

 might engage the attention of a larger circle of listeners. 



From this point of view I would ask you to consider my 

 deductions on the subject of the Origin and Development of 

 the Mammalian Phylum. 



Of all Vertebrates, Mammals are the last to appear upon 

 the earth ; we find their earliest remains scantily represented 

 in Triassic formations. While they very soon secured the 

 mastery for themselves, so that we may designate our geolo- 

 gical period as that of the Mammals, before their appearance 

 the phylum of the Sauropsida was predominant. It is there- 

 fore quite natural to commence with tlie consideration of the 

 latter if we would make a closer acquaintance with the 

 question of the origin of Mammals. 



We can gain no idea of the extraordinary wealth of foi-ms 

 in the reptilian class by considering the lizards, snakes, 

 chelonians, and crocodiles which are at present in existence. 

 These are merely the last miserable shoots of a once far- 

 spreading tree, which embraced more than double the number 

 of orders ; we can gain no comprehensive view of them until 

 we examine the remains which the strata of the earth have 

 preserved for us. On the basis of the palgeontological disco- 

 veries which multiply from year to year, we are enabled to 

 trace the phylogeny of the reptiles, at least in its main out- 

 lines, with tolerable certainty. 



The Eeptiles, which did not appear on our earth until after 

 the Fishes and Amphibia, have their earliest known represen- 

 tatives in the Permian formation, which belongs to the 

 Palaeozoic period. The Progonosauria, as they are called, 

 are tvpes which have as yet undergone but little specializa- 

 tion "and combine in their organization the characteristics of 

 all other orders of reptiles. Like a relic from remote anti- 

 quity, a descendant of these old forms projects into the 

 present, represented by the genus Hatteria^ which occurs 

 only in New Zealand. 



Almost simultaneously with the Progonosauria, and allied 



