THE FIRST INTERNATIONAL OENITHOLOGICAL CONGRESS, 1884. 
61 
into the discussion of the international protection of birds. 
The proceedings were opened by an address by Dr. Bernard 
Altum, one of the greatest authorities of the time, the famous 
Professor of the Academy of Forestry at Eberswalde. 
The speaker, in addition to the agricultural significance 
of birds, emphasised their aesthetic value as well, creating 
an entire system in this respect, the scheme of which is as 
follows: 
1. Aesthetic significance: 
a) pleasant form. 
2. Colour and shape: 
according to 
a) zones, 
b) seasons, 
c) time of day, 
^ d) habitation, 
e) sex and age. 
3. Movement, peculiar flight. 
4. Musical powers: 
a) mechanical (the pecking of woodpeckers, the piping 
of the common snipe), 
b) organic (voice and song); according to 
I. season, 
II. time of day (2 categories, day and night singers), 
III. surroundings, 
IV. society, 
V. relationship. 
The essence and significance of bird-songs. 
This immense perspective, the opening of which betrayed 
an absolutely German intellectual power, and was only loosely 
connected with the practical, i. e. the prosaic part of the 
bird question, did not have the effect on which its author 
reckoned. But he had something to say of the practical side 
