IF Mr. Stapley, who wrote on this subject in last week's NATURE, can refer to Dr. H. Muller's treatise on the relations between flowers and insects, in the first volume of Shenk's Handbuch der Botanik (now publishing as part of Trewendt's Encyclopaedie der Naturwissenschaften), he will see that his own observations are very similar to those of Dr. Muller. The latter, however, refers to and figures the Germander, not the Common, Speedwell. Is it possible that Mr. Stapley—who speaks of the Veronica officinalis as having larger flowers than the V. hederaefolia, whereas they have flowers of about the same size—mistakes the V. chamaedrys for the V. officinalis?