322 REPORTS ON THE STATE OF SCIENCE, ETC. 
One Number Two Number 
Strength. Generation. Tested. we Tested. 
0°30 98 40 — — 
0°35 43 54 = — 
0°37 go 40 Te = 
0°40 62 314 63 30 
0°43 — Fis 63 27 
0°44 73 33 = — 
0°45 58 259 65 49 
0°46 sy — 79 63 
0°47 15 97 97 36 
0°48 a scr 65 54 
0°49 26 78 67 30 
0°50 37 135 51 105 
0°51 eos oa 39 52 
0°52 = Tr 75 99 
0°53 a ar 48 104 
0°54 = aa 57 21 
0°55 aii 7° 34 154 
1,120 824 
In both cases it is difficult to avoid the conclusion that the strength of 
poison needed to produce a given death-rate has been increased by at least 
10 per cent., and probably more for the bisexual material. Many of the 
individual percentages are based on quite small numbers, but the series are 
distinctly more irregular than homogeneous material would give. 
Another result of the tests hitherto made is that, in spite of the irregu- 
larity in the response to arsenic treatment, there appears to exist a difference 
in the susceptibility between the diploid bisexual and the octoploid 
parthenogenetic forms; the latter have a considerably wider range of 
resistance than the former. In the bisexual races the 50 per cent. point of 
survival lies well under 0-5 per cent. arsenite, whereas in several lines of the 
octoploid parthenogenetic races 100 per cent. of the nauplii survive this 
strength, and even 0:6 per cent. 
The Committee ask to be reappointed. 
BIOLOGICAL MEASUREMENTS. 
Report of Committee appointed to revise the leaflet on Biological Measure- 
ments and to consider what steps should be taken to increase the use made 
of the archives for the reception of such measurements now established 
at the British Museum (Natural History), South Kensington (Prof. J. S. 
Huxiey, Chairman; Prof. R. A. FisHer, F.R.S., Secretary; Dr. 
W. T. CaLman, F.R.S., Dr. J. Gray, F.R.S.). 
THE Committee have revised and enlarged the leaflet on Biological Measure- 
ments, first issued in 1927, of which the first edition has been exhausted. 
The leaflet is now published separately from this Report, and is obtainable 
price 6d., or 7d. post free, from the offices of the British Association, Burling- 
ton House. 
The following journals now include in their notice to contributors in- 
formation as to the archives for the reception of bodies of provisional data 
