78 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. b 
adapted to suit their surroundings through the action of 
natural selection, but there seem to be the four following 
alternatives as to the present position of affairs :— 
1. There may be the 4 above noted (and possibly others) 
colours of individuals as 4 distinct varieties, which produce 
young of their own colours, keep to their own special 
habitat, and do not inter-breed. This I think unlikely. 
2. ‘There may be no permanent varieties, but the young 
when they first settle down upon the sand or sea-weeds 
may, whatever their colour may be, have great adapt- 
ability, so that under the influence of their environment 
they soon assume a protective colouration. This would 
be a case of ‘‘direct action of the environment,” partly 
perhaps due to food. 
3. This adaptability—or marked susceptibility to the in- 
fluence of environment—may possibly be retained through- 
out adult life, so that conceivably a green Virbiws might 
migrate from the Zostera bed to a clump of Halidrys, and 
then change froma green to a dark brown colour. 
4. lastly, the young of all 4 colours may present great 
varlation in tint, and then under the action of natural 
selection those which are not specially fitted to their sur- 
roundings in each case will be eliminated. 
Tam inclined myself to regard the last as the most prob- 
able explanation, but we have arranged to start some 
experiments and observational broods at the Biological 
Station which it may be hoped will throw some light upon 
these and other similar cases. 
OTHER F'AUNISTIC WORK. 
Looking at the additions to the ‘“‘ Fauna” during the 
year :—Mr. A. O. Walker records amongst Amphipoda, in 
addition to those noted above, Harpinia neglecta, Sars, 
(noted before as H. plwmosa), Colwyn Bay and Port Erin, 
ene er 
