In the summer of 1921, with the assistance of a grant from the Royal Society and the Cambridge Worts Fund, I spent rather more than two months in Western Greenland. It was mainly through the kind offices of my friend Prof. Ostenfeld, of Copenhagen, that the necessary permission to visit the Danish Colony was obtained. Mr. R. E. Holttum, who is now Assistant Director of the Botanic Garden, Singapore, acted as my Research Assistant, and did more than his share of the hard work. We left Copenhagen on June 18 and arrived at Godthaab at midnight on June 28; at Egedesminde, which we reached on July 2, we left the steamer and crossed Disko Bay in a motor-boat to Godhavn, on Disko Island. At Godhavn we were received by Mr. Morten Porsild, the Director of the Danish Arctic Station. Two motor-boat expeditions were made from Godhavn—the first along the south-east coast of Disko Island as far as Ritenbenk’s coal mine; and the second, in the course of which we travelled more than 500 miles, along the south-west coast of Disko Island to Hare Island, Upernivik Island and the Nûgssuak Peninsula, where several exposures of Cretaceous strata were examined. All arrangements were made for us by Mr. Porsild, whom it is impossible adequately to thank for his invaluable help and uniform kindness; his son, Mr. Erling Porsild, accompanied us as interpreter, and by his intimate knowledge of the country and of the local flora rendered very valuable service. A general account of the present vegetation has been published by Mr. Holttum. Specimens of the recent plants which we collected, supplemented by gifts from Mr. Porsild’s herbarium, have been deposited in the herbaria of Kew, the British Museum, and the Cambridge Botany School. In a popular account of the expedition, published in 1922, acknowledgment was made of the assistance received from botanists in the determination of the non-vascular plants.