In a letter in the last Number of the GEOLOGICAL MAGAZINE, Mr. Jukes-Browne takes me to task, with some asperity of language, for my views on the true horizon of the Mammoth, You will, I am sure, allow me to reply to him. He speaks of my “looking down from some literary height upon practical geologists in the plain,” and goes on to say that I have “no practical experience as a geologist, and bids me study the facts in the field.”