26 



SPORES OF OTHER FUNGI CARRIED BY THE INSECTS. 



The results obtained in the cultures show that 10 of the 19 

 insects brought in from the field and yielding positive results 

 carried a larger number of spores of the blight fungus than of 

 all other fungi combined^ and three of these (Nos. 22, 44, and 

 48) were not carrying any other fungous spores. In addition, 

 insect No. 30, which yielded the highest positive results ob- 

 tained (Fig. 3), gave almost pure cultures of the chestnut 

 blight fungus. 



The number of species of fungi other than Endothia para- 

 sitica represented in the cultures varied from 0 to 7 per insect, 

 and those which appeared most frequently were species of 

 Penicillium and Cladosporium. Little attempt was made to 

 identify those species less frequently met with, especially if 

 they did not fruit in culture. 



As was the case in the work on the birds, the microscopic 

 examination of the centrifuged sediments revealed the fact 

 that a larger number of species of fungi was carried by at least 

 some insects than was indicated in the cultures. The determin- 

 ation of (he number of species carried was based upon the 

 cultures and on the microscopic examination of the centrifuged 

 sediments. In the latter the size, form, septation, and colora- 

 tion of the spores were taken into consideration. One form in 

 particular was frequently found in the sediments, which never 

 appeared in the cultures, probably on account of its slow 

 growth. This was a species of Coryneum. It is our opinion 

 that the number of fungous spores carried was very likely 

 greater in every case than was shown by the cultures (Table 

 I). 



The fungous spores, other than those of the blight fungus, 

 found in the sediment from insects Nos. 44 and 64 are repre- 

 sented in Figs. 4-24. In the sediment from the latter insect, 

 10 different kinds of spores were found, while only 2 species of 

 fungi other than the blight fungus appeared in the cultures. 

 In the former the numbers were 7 and 0 respectively. 



