BY the end of this year, the Edinburgh Geological Society will have been in existence for one hundred years. In order to take advantage of the presence in Scotland of many foreign and overseas geologists who will be attending the Aberdeen meeting of the British Association, it has been decided to hold the centenary celebrations early in September. Invita tions have been sent to learned societies at home and abroad, and a large number of delegates will take part with the fellows of the Society in various functions. On Monday, September 3, the delegates from kindred societies will be received in the buildings of the University of Edinburgh, where they will be welcomed by the president, Sir John Flett, in the name of the Society, and by Sir Thomas Holland, in the name of the University, During the afternoon, visits will be paid to the Royal Scottish Museum and the offices of the Scottish branch of H.M. Geological Survey. In the evening, the Society and its visitors will be the guests of the Lord Provost and Town Council of Edinburgh at a reception in the College of Art. Tuesday morning will be devoted to hearing short addresses by eminent geologists in the new Geological Department of the University. The party after lunch will make a tour of various places of geological interest in and around Edinburgh. A dinner on Tuesday evening given by the Society to the visiting representatives will bring the functions to a close.