48 



about 70 per cent, individuals already dead from the disease. 1 The 

 same day all the material was exposed, with the assistance of Mr. Gras- 

 sie, in the western part of the selected place, and about 6 feet from 

 the ground. Most of the caterpillars of this locality were at this 

 time about ready to undergo the fourth molt. 



On Sept. 26, 1910, the island was visited again, in company of the 

 local superintendent, to determine in what manner the wilt had op- 

 erated among the caterpillars. An especially considerable reduction 

 of the number of the fresh egg clusters, compared with those of the 

 previous year, had not occurred. According to our estimate there were 

 about 1,500 fresh clusters. The size of each of these clusters, com- 

 pared with the clusters found in the spring of 1910, was diminished 

 in such a degree, however, that the clusters were often no larger than 

 a bean. The eggs also were often only covered in part with hair. This, 

 as well as the comparatively small mortality and the smallness of the 

 fresh clusters, may be perhaps a consequence of the late planting of 

 the disease. It is true that a number of caterpillars were killed, but 

 most of them only grew slightly sick, the disease again expressing it- 

 self at the time of oviposition. The fresh clusters of this locality were 

 also of an abnormally light yellowish color, which was noticed nowhere 

 else. 



The examination of the first 5 clusters found gave the following re- 

 sult: 



Unfertilized eggs, . 

 Eggs with dead embryos, 

 Eggs apparently alive, . 



Total, f 



Cluster 1. 



4l 



? = 6.36 per cent., or about 6 per cent. 



162 =93.64 per cent., or about 94 per cent. 

 173 eggs. 



Unfertilized eggs, . 

 Eggs with dead embryos, 

 Eggs apparently alive, . 



Total, 



Cluster 2. 



3 

 15 



58 



76 



=23.68 per cent., or about 23.5 per cent. 

 = 76.32 per cent., or about 76.5 per cent. 



Unfertilized eggs, . 

 Eggs with dead embryos, 

 apparently alive, . 



Total, 



Cluster 8. 



Q > = 12.28 per cent., or about 12 per cent. 

 50 =87.72 per cent., or about 88 per cent. 



57 eggs. 



1 It should be mentioned that Mr. Grassie sent a telephone communication on June 12, 1910, 

 that the wilt had made its appearance among his caterpillars, but by a mistake I did not receive 

 this notice until June 23. 



