XXXIV Obituary Notices of Fellows deceased. 
races were far from occupying the whole of Weldon’s thoughts in these early 
days. In conjunction with his assistant, Dr. E. Warren, he had commenced 
at University College his first big experimental investigation into heredity. 
The characters dealt with consisted of the number of scales in particular 
colour patches upon certain pedigree moths, and the work of counting these 
was very laborious. In the course of three years, many hundreds of pedigree 
moths were dealt with, and the observations were reduced. But no definite 
inheritance at all of the character selected for consideration was discovered. 
Weldon, apparently thought that there had been some fatal mistake in the 
selection of pairings, and undoubtedly, in some cases, parents of opposite 
deviation had been mated, so that a rather influential negative assortative 
mating resulted. But from other series of pedigree moth data, it seems 
probable that there is some special feature in heredity in moths, or possibly in 
those that breed twice in the year, and that the vast piece of work which 
Weldon and Warren undertook in 1898—1901 may still have its lesson to 
teach us. | 
In these three first years at Oxford, Weldon’s intellectual activity was 
intense. To the pedigree moth experiments was added, in the summer of 
1900, an elaborate series of Shirley Poppy growings, 1250 pedigree individuals 
being grown and tended in separate pots; Weldon’s records were the most 
perfect of those of any of the co-operators, and his energy and suggestions 
gave a new impetus to the whole investigation. They were ultimately 
published in ‘ Biometrika’ under the title, “ Co-operative Investigations on 
Plants, I. On Inheritance in the Shirley Poppy.” As Weldon himself 
expressed it, the moths and poppies meant “a solid eight hours daily of 
stable-boy work through the whole summer and through the Easter vacation, 
with decent statistical work between.” After the Shirley Poppies were out 
of hand in the summer of 1900, the Weldons went to Hamburg and thence 
to Plon. The object of this visit was to collect Clawsilia at Plon and 
Gremsmiihlen for comparison with the race at Risborough. The same 
aim—the comparison of local races—led Weldon at Christmas to collect 
land-snails in Madeira. Thus he slowly built up a magnificent biometric 
collection of snail shells, z.¢., one sufficiently large to show, in the case of 
many local races of a number of species, the type and variability by statis- 
tically ample samples. Of this part of his work only two fragments have 
been published, “ A First Study of Natural Selection in Clausilia laminata” 
(Montagu) and “ Note on a Race of Clausilia itala” (von Martens). In the 
first of these memoirs he shows that two races of (. laminata exist, in 
localities so widely separated as Gremsmiihlen and Risborough, with sensibly 
identical spirals, although no crossing between their ancestors can have 
existed for an immense period of time, and although there are comparatively 
few common environmental conditions. At the same time, while no differ- 
ential secular selection of the spiral appears to have taken place during this 
period, there yet seems to be a periodic selection of the younger individuals 
in each generation, the variability of the spirals of the young cells being 
