Lect. IX.] EXPANSION OF MODEEN THOUGHT. 229 



galleries ; the organs of special sense, with their labyrinthic passages, 

 their fringed curtains, and carved porches ; the tongue, doubly port 

 cullised with the teeth and lips; and, indeed, the whole of this 

 clay-compounded Man, is but a curiously modified repetition of all 

 that we are familiar with in the Mammalia, generally, that seem 

 so far below us. 



I have, in. the Ninth Lecture, commented upon the new connection 

 of the three great branches of modem science. I may, in conclusion, 

 remark further that those who are familiar with the English litera- 

 ture of the seventeenth century know that, during a few decades, the 

 minds of thinking men became to a remarkable degree enfranchised 

 and expanded in all that relates to the motions of the heavenly bodies, 

 and, indeed, as to the idea of the Cosmos as a whole. 



Another great and healthy growth of human thought took place 

 at the latter end of the last, and the beginning of the present, cen- 

 tury, when the fathers of modern Geology gave us theu' researches 

 and deductions. 



Of course, time was not excluded from the thoughts of the great 

 discoverers of modern Astronomy ; but Geologists, taking this one 

 moving globe, the earth, for their field of labour, found a most in- 

 valuable approximative measure of secular periods in the study of 

 the fossUiferous strata. 



Modern Biology was germinant in the Palaeontologioal department 

 of Geology ; it could not fail to come into active life when the days 

 of its appointed time had come. These three great births of human 

 thought — Astronomy, Geology, Biology — belong to us and to our 

 children. 



KEILL AND COMPANY, BPINBURGH, 

 PRINTBR8 TO IlEE MAJESTY'S STATIONERY OFFICE. 



