REPORT OF THE COMMITTEE, CONSISTING OF MR. GALTON (CHAIRMAN), MR. F. DARWIN, PROF. MACALISTER, PROF. MELDOLA, PROF. POULTON, AND PROF. WELDON, "FOR CONDUCTING STATISTICAL INQUIRIES INTO THE MEASURABLE CHARACTERISTICS OF PLANTS AND ANIMALS."

PART I.-AN ATTEMPT TO MEASURE THE DEATHRATE DUE TO THE SELECTIVE DESTRUCTION OF CARCINUS MENAS WITH RESPECT TO A PARTICULAR DIMENSION.

BY

PROF. WELDON, F.R.S.

Report of the Committee, consisting of Mr. Galton (Chairman), Mr. F. Darwin, Professor Macalister, Professor Meldola, Professor Poulton, and Professor Weldon, "for Conducting Statistical Inquiries into the Measurable Characteristics of Plants and Animals." Part I. "An Attempt to Measure the Death-rate due to the Selective Destruction of Carcinus Manas with respect to a Particular Dimension."-Drawn up for the Committee by Professor WELDON, F.R.S. Received November 20, 1894.

Among the material available for the purposes of the Committee was a sample of Carcinus manas, from Plymouth Sound, including a fairly large number of young females. The distribution of abnormalities in certain dimensions had already been determined for adult females from the same locality (Roy. Soc. Proc.,' vol. 54, pp. 318-329); and it seemed worth while to compare the frequency of abnormalities in young individuals at various stages of growth with the frequency of the same abnormalities in adult life, so as to determine whether any evidence of selective destruction during growth could be discovered or not.

About 7000 females, varying in length from 700 to 13.95 mm., were chosen (at random, except as regards their size), and two dimensions were measured in each. The results were then compared with those of the corresponding measurements, made upon a sample of 1000 adult females from the same locality, which are recorded in the paper just referred to.

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