34 TEANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



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 adaptabihty — or marked susceptibility to the in- 

 fluence of environment — may possibly be retained through- 

 out adult life, so that conceivably a green Virhius might 

 migrate from the Zostera bed to a clump of Halidrys, and 

 then change from a green to a dark brown colour. 



4. Lastly, the young of all 4 colours may present great 

 variation 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. 



I am 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. 



Othee Faunistic Work. 



Looking at the additions to the "Fauna" during the 



year: — Mr. A. 0. Walker records amongst Amphipoda, in 



addition to those noted above, Harpinia neglecta, Sars, 



(noted before as H. plumosa), Colwyn Bay and Port Erin, 



