476 
Dr. A. L. Thomson : Results of a Study of [Ibis, 
The numbers, sizes, and destinations of all rings issued to 
markers were carefully noted and reappearances of marked 
birds were checked by these notes. Along with the rings 
were sent schedules on which the data about all birds marked 
were to be filled in, the following information being asked 
for :—(1) Number on ring ; (2) Species of bird ; (3) Date 
of marking and release; (4) Locality of marking and 
release; (5) How obtained (“ as young,” etc.); (6) Sex 
and age so far as certain ; and any other remarks, including 
bracketing together members of the same brood with word 
to that effect. When the completed schedules were returned, 
the data were transcribed into ledgers, in which the entries 
were arranged serially according to the ring numbers, a final 
column being left blank for the purpose of entering references 
to the “ Case numbers ” in the separate card-index of re¬ 
appearance records. 
When a marked bird was reported as killed or recaptured, • 
the number on the ring was the chief thing required, 
together with a note of the locality and approximate date of 
the occurrence. If the ring, 'with or without the foot, were 
sent, or if the species were identified, an additional check on 
the accuracy of the record was provided. Many birds were 
naturally recorded from the places where they were marked, 
and the interest of these records depended on the lapse of 
time and on the other circumstances of the case : cognisance 
was taken of all records of this kind, however, except when 
a bird was recorded on the same day, or, in the case of young- 
birds, within the flightless period. 
At the outset of the investigation no restriction was made 
as to the species of birds which were to be marked, and each 
co-operator was left to make use of whatever opportunities 
he might have. These opportunities were for the most part 
confined to young birds as yet unable to fly, but large 
numbers of birds were also caught in nets set up for the 
purpose and a few were caught at lighthouse-lanterns or at 
night on the sea-shore. It was felt that the widest possible 
scope would provide the fairest test of the value of the 
