21 



With the assistance of the local superintendent the whole breeding 

 material was immediately exposed in the western part of the selected 

 forest. The distance from the ground to the material, which was hung 

 between the limbs of a tree, was about 15 feet. The largest number of 

 gypsy moth caterpillars in this locality were at this time in the third 

 molt, or about to pass into this molt. The wilt soon spread over 

 the whole forest, as was seen during occasional visits to the place 

 by Mr. Richardson, Mr. Brewster and myself. On Sept. 7, 1910, the 

 fresh egg clusters were estimated by the local superintendent and 

 myself to amount to about 5,000. Often 4 or 5 of these clusters to- 

 gether would not make more than 1 normal cluster; the actual number 

 of eggs was thus much less than would have been present in the same 

 number of normal clusters. 



The examination of 5 clusters which had been collected Sept. 7, 

 1910, on Brewster's estate showed the following counts : 



Unfertilized eggs, . 

 Eggs with dead embryos, 

 Eggs apparently alive, . 



Total, 



Cluster 1. 

 3 



9.66 per cent., or about 9.5 per cent. 

 131 =90.34 per cent., or about 90.5 per cent 



145 eggs. 



Unfertilized eggs, . 

 Eggs with dead embryos, 

 Eggs apparently alive, . 



Total, 



Cluster 2. 



2) 



9 > =7.43 per cent., or about 7.5 per cent. 



137 =92.57 per cent., or about 92.5 per cent. 



148 eggs. 



Unfertilized eggs, . 

 Eggs with dead embryos, 

 Eggs apparently alive, . 



Total, 



Cluster 8. 



13 1 



^g \ =48.06 per cent., or about 48 per cent. 



67 =51.94 per cent., or about 52 per cent. 

 129 eggs. 



Unfertilized eggs, . 

 Eggs with dead embryos, 

 Eggs apparently alive, . 



Cluster 4. 



= 8.64 per cent., or about.8.5 per cent. 

 74 =91.36 per cent., or about 91.5 per cent. 



Total, 



81 eggs. 



