In David M. Wilkinson's Correspondence letter "Brown knew particles were smaller than pollen" (Nature 434, 137; 200510.1038/434137c), the sentence "The microscopic particles involved in the characteristic jiggling dance Brown described were much smaller clay particles" should not have contained the word "clay", which was added in error during the editing process. The particles Brown saw were inside the pollen grains.
Correspondence
Nature 434, 435 (24 March 2005) | doi:10.1038/434435d; Published online 23 March 2005