72 NEW YORK ZOOLOGICAL SOCIETY. 



south end of the new Bird House, was excavated and filled with 

 good soil from the bed of Lake Agassiz, as also was the space for 

 the northern grass plat. 



In order to remove from the Buffalo Range the poisonous 

 grasses and infected earth which in previous years had so seri- 

 ously afifected the buffalo herd, the top soil was removed from 

 the whole of that area, and utilized in making new ground for 

 plantings at the New Boston Road Entrance. In the spring of 

 1906 that range will be seeded with red-top grass, which it is 

 believed will not affect the buffaloes adversely. 



At the eastern end of the new bridge across the Bronx River, 

 on Pelham Avenue, the southern sidewalk space was left by the 

 bridge contractor as a chasm, about 12 feet wide, 14 feet deep, and 

 100 feet long. This space was filled with earth from Lake Agas- 

 siz, shaped into a proper embankment, and finally the side of the 

 embankment was covered with top soil and seeded. 



Owing to the presence of filaria in the bottom of the Elk Pond, 

 the water from the bottom of which could not be drained off, 

 about 1,700 yards of earth, stones, etc., were hauled and depos- 

 ited there to raise the level of the bottom high enough to drain the 

 pond and disinfect it. 



The site of the yards to surround the new house for Small 

 Deer, and the surrounding walk, was carefully graded, and a 

 great quantity of earth filling was hauled in to fill the hollow on 

 the western side of the slope. This was not completed during 

 1905. 



The entrance plaza for the new Boston Road Entrance was 

 unavoidably located on a spot which was about ten feet below the 

 level of the adjacent streets. Part of this hollow was filled with 

 about 3,000 yards of top soil, as a basis for planting operations. 

 The remaining space was filled with other materials, and graded 

 up as near as practicable to the lines of the north retaining wall, 

 and the macadam surface that remains to be added. One hundred 

 cubic yards of specially selected stone, for the north retaining 

 wall of this plaza, were purchased on the site of the city's Grand 

 Concourse, near Jerome Avenue, and hauled to the site of the 

 proposed improvement. 



Lake Agassiz. — Very important work was done in Lake 

 Agassiz and vicinity. First, the solid masonry core of the earth 

 island between the two waterfalls, once overflowed by a heavy 

 flood with great damage to the island, was raised three feet, 

 effectually preventing similar occurrences in the future. The 

 whole surface of the island was raised about four feet by de- 



