50 



dition of the brood, I inspected the caterpillars July 1, 1910, and found 

 that about 60 per cent, of them had succumbed to Tlacherie. The first 

 dead caterpillars were noticed by Mr. Young about fifteen days before. 

 On the same day the whole of the material was exposed, with Mr. 

 Young's assistance, in the southwestern part of the island, about 5 feet 

 from the ground. Most of the caterpillars of this locality had at this 

 time just undergone the fourth molt. 



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

 local superintendent. We could see that the wilt had done very con- 

 siderable damage to the caterpillars, for there were only a few scattered 

 clusters. According to our estimate there were hardly 15 fresh clusters 

 present; these, moreover, were much smaller in size than those of the 

 previous year. It was also noticed that the clusters were often only 

 partly covered with hair. All these conditions may well be attributed 

 to riacherie. The almost full-grown caterpillars had contracted the 

 disease, and the females which then emerged from pupae produced by 

 these caterpillars were unable to oviposit like healthy moths. 



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

 sult : — 



Cluster 1. 



3] 

 j^Q ) = 9.56 per cent., or about 9.5 per cent. 



t 90.5 per cent. 



Unfertilized eggs, . 

 Eggs with dead embryos, 

 Eggs apparently alive, . 



Total, 



. 123 =90.44 per cent., or about ! 



136 eggs. 



Unfertilized eggs, . 

 Eggs with dead embryos, 

 Eggs apparently alive, . 



Total, 



Cluster S. 



^2 } = 8.82 per cent., or about 9 per cent. 

 155 =91.18 per cent., or about 91 per cent. 



170 eggs. 



Unfertilized eggs, . 

 Eggs with dead embryos. 

 Eggs apparently alive, . 



Total, 



Cluster S. 



•J } = 4.73 per cent., or about 4.5 per cent. 

 161 =95.27 per cent., or about 95.5 per cent. 



169 eggs. 



Unfertilized eggs, . 

 Eggs with dead embryos, 

 Eggs apparently alive, . 



Cluster 4- 



2\ 



g I = 10.77 per cent., or about 10.5 per cent. 



58 =89.23 per cent., or about 89.5 per cent. 



Total, 



65 eggs. 



