Noies and Comments. 51 
HABITS OF BLACK-HEADED GULL. 
At a recent meeting of the Linnean Society, Mr. T. A. 
Coward read a paper on ‘ A Change in the Habits of the Black- 
headed Gull.’ Owing to the remarkable increase in its numbers 
since the Wild Birds’ Protection Act of 1880, this Gull has 
extended its range inland, and it is now an inland as well as a 
shore bird. This increase, in North Cheshire, has resulted 
in a noticeable change of habit, secondary to the change 
mentioned above, for within the last few years the bird has 
been roosting nightly on the waters of Rostherne Mere during 
autumn, winter and early spring. Normally, the roosting 
and feeding hours of a bird which feeds upon the coast are 
regulated by the tides, but these Cheshire birds retire to roost 
like any other diurnal bird, about sundown. The area which 
these regular diurnal feeding and nocturnal sleeping Black- 
heads frequent, is contiguous to an area where others of the 
same species feed and sleep according to the constantly changing 
hours of the tide in the neighbouring Mersey estuary. 
PLANTS AND LIGHT. 
Dr. Harold Wager’s evening discourse delivered before the 
British Association at Manchester on the behaviour of plants 
in response to the light, is printed in Nature for December 
23rd. It is illustrated by a remarkable series of photographs 
showing the effect of light upon leaves, etc. In accounting 
for this, Dr. Wager says: ‘ We may imagine that in the plant 
the action is as follows :—The light is absorbed by, and excites, 
certain photo-active substances in the cells of the sensitive 
region. A stimulus is thus set up which is conveyed through 
the cytoplasmic fibrils of the protoplasts to the motor region. 
A further impulse is then set up which acts upon the cells 
in the motor region, by which it is probable that changes in 
the permeability of the protoplasts are effected; the turgor 
conditions of the cells are thereby differentially altered, and 
the result is a motor response. We have here, in fact, a very 
simple type of reflex act taking place through the agency not 
of highly specialised nerve-cells, but of ordinary protoplasm 
and of the delicate protoplasmic fibrils which extend from 
one cell to another.’ 
SUSSEX BIRDS. 
We think the above would be a better title for our ornitho- 
logical contemporary, british Birds, as the first part in the 
new year is almost entirely occupied with Sussex records 
“seen in the flesh,’ and several are ‘ new to the British list.’ 
They are ‘ Moustached Warbler in Sussex ’ (shot) ; ‘ Olivaceous 
Warbler in Sussex ’ (shot) ; ‘ North African Black Wheatear in 
Sussex ’ (shot); ‘Cape Verde Little Shearwater in Sussex’ 
4916,Feb. 1. 

