LECT. IX.] EXPANSION OF MODERN 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 modern 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 modem Geology gave us their 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 fossiliferous strata. 



Modern Biology was germinant in the Palseontological 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. 



NEILL AND COMPANY, EDINBURGH, 

 PJ1INTKR8 TO IIKlt MAJESTY'S STATIONERY OVFICK. 



