114 PROCEEDIXGS OF THE LIXXEAX SOCIETY OF LOXDON. 



Pearson, and Professor C. P. Davenport, a new joiu'nal, ' Pio- 

 metrika,' to which he continued to contribute important statistical 

 papers up to the time of his death. Unfortunately much of the 

 work upon which he was engaged during the last few years 

 remains unpabHshed, Much of it was of an exceedingly laborious 

 and time-consuming nature. It would be difficult to give an idea 

 of the technical difficulty and time required to collect the data for 

 his paper on the study of Natural Selection in Clausilia laminaia, 

 published in the first number of ' Piometrika.' It involved the 

 grinding down by hand of hundreds of fragile shells, and afterwards 

 carefully measuring them. He continued these investigations 

 amid much other work , from 1902-1906, and had prepared a 

 number of sections for a similar paper upon snails of the genus 

 Helicc, but the work was left untinished. He had been for the 

 last four years deeply engaged in a controversy on the validity of 

 Mendel's law, and many of his friends regretted that he took up from 

 the first such an attitude of uncompromising opposition to Avhat 

 seemed to many to be a most promising instrument of research. 

 But his attitude was hardly understood. He demanded more exact 

 definitions and a more rigorous proof founded upon a larger number 

 of instances than the adherents of Mendel were prepared to give 

 in the earlier stages of the controversy; and when, true to his own 

 principles, he put Mendel's hybridization results to proof, he found 

 discrepancies which he was unable to reconcile by the exact 

 statistical methods which he employed. He spared no pains to 

 arrive at the truth, and instituted experiments on the hybridization 

 of domesticated races of mice on a very large scale. Some of the 

 results of these experiments have been published by his pupils 

 Mr. E. A. Schuster and Mr. A. D. Darbishire ; but the enquiry 

 Mas still in progress at the beginning of the present year, and the 

 data have been carefully collected and will form the subject of a 

 posthumous memoir by Professor Karl Pearson. 



Weldon had also projected and had written some part of a book 

 on the Statistical aspect of Heredity and Variation, audit is hoped 

 that the chapters left completed at his death may give a clue to 

 his latest opinion on the subject. 



These few fragments descriptive of an energetic scientific life 

 will serve to show how great was the loss sustained by Zoology 

 when so exact and yet so original an investigator was cut off in the 

 fulness of his powers. Much as he had already done, Weldon had 

 much more to accomplish, and he had set himself work from which 

 results of the highest importance must have been derived. Peyond 

 the loss to scientific thought there is the loss, to a large circle of 

 friends, of one whose high character, affectionate and generous 

 disposition, combined with wit and humour, leaves a void which 

 cannot be filled. Multis ille honis fiehilis occidii ! [G. C. P.] 



