The following notes on the laterites of Western Australia are the outcome of a careful study of the series of articles contributed to the Geological Magazine during the latter part of 1911 by Dr. L. Leigh Fermor, entitled “What is Laterite?” These deal with the subject from the point of view of one having an intimate knowledge of Indian laterite, but not a first-hand acquaintance with those of other parts of the world. The present writer, during the last fifteen years, has devoted much time to the study of the laterite of extratropical Western Australia, both in the field and in the laboratory, and is therefore in a position to supplement some of the work of Dr. Fermor, whilst inclined to differ from him in some of his deductions.