Finn’s Experiments 
It is obvious that there is a wide field for 
observation on these lines. In the case of large 
birds the experiment could be made still more 
conclusive by confining the three birds to be 
experimented on in a single enclosure, divided 
into three compartments by fences. The males 
should be placed each ina separate compartment, 
and have a wing clipped so as to prevent them 
leaving their respective compartments, while the 
hen should be allowed the power of flight so that 
she can visit at will any compartment. 
Finn has also recorded (doc. cz¢.) some other 
observations bearing on the question of sexual 
selection. He writes :— 
“One cannot observe or read about the habits 
of birds very much without finding out that, 
whatever may be the value of beauty, strength 
counts for a great deal. Male birds constantly 
fight for their mates, and the beaten individual, 
if not killed, is at any rate kept at a distance by 
his successful rival, so that, if he be really more 
beautiful, his beauty is not necessarily of much 
service to him. I was particularly impressed 
by this about a couple of years ago, when | 
frequently watched the semi-domesticated mal- 
lards in Regent’s Park in the pairing season. 
These birds varied a good deal in colour; in 
some the rich claret breast was wanting, and 
others had even a slate-coloured head instead of 
the normal brilliant green. Yet I found these 
313 
