50 ORAL EQUIPMENTS. 



of a very simple pattern. Yet remember they arc distinctly 

 of the Mammalian character, being attached by " gomphosis," 

 i.e., in a socket. 



Now I propose for to-night to show that if the Mammalia 

 lose numerically in their oral armature, this is amply made 

 up for by a most interesting and wonderful specialisation of 

 structure to meet the exigencies of their environments. 



I have prepared a list in a tabular form to show roughly 

 the proximity of relationship of the various species of Mam- 

 mals, as at present known to Zoologists, and I have indicated 

 with larger capitals those creatures which I consider present 

 the most interesting and well-marked characteristics for such 

 a brief and discursive paper as that of this evening. 



It not being my object to enter into the subject of the 

 classification of Mammals, further than is necessary for the 

 understanding of their oral structures, I will state that a 

 description of the teeth of the Placental Mammals will suffice 

 for the Implacental genera also, as they are differentiated 

 according to their modes of life on the same lines as their 

 Placental brethren. It is a very singular fact however, and 

 one worthy of note here, that the Implacental Mammalia are 

 confined almost exclusively to Australia and a small portion 

 of South America ; and where they are now, geology tells 

 us they have existed in past geological ages, and almost to the 

 exclusion of the Placental order of beings. 



In comparing the teeth and jaws of Mammals, we find 

 that they may be roughly referred to three leading types, 

 according to the sort of food the creature lives upon ; and as 

 the teeth are specialized to meet these requirements, so 

 according to the great biological law of " correlation of 

 growth" of the parts of an animal, do we find the jaws 

 differentiated. 



By-the-bye, in passing, it is worthy of mention that the 

 great Owen, the greatest osteologist I suppose that has ever 

 lived said, according to this law of " correlation of growth " 

 or " concomitant development," a thoroughly proficient osteo- 

 logist ought to be able to portray any animal and build it up 

 bone for bone exactly as it has existed, on seeing one bone or 

 even one portion of a bone." 



Thus we have teeth and jaws indicating by their structure 

 a vegetable diet, and so their owners are called Herbivora. 

 You will not find this name on the table of animals before 

 you, for the simple reason that a vast number, although sub- 

 sisting on a vegetable diet, have been classified in accordance 

 with some special feature. Thus we find Elephants though 



