28 



13. A microscopic examination of the centrifuged sediments 

 showed a very few ascospores, and these from only five insects. 

 Pycnospores were present in the sediment from every insect 

 yielding positive results. 



14. The insects tested, even Leptostylus macula^ which eats 

 the pustules, were therefore carrying pycnospores almost ex- 

 clusively. 



15. Most of the pycnospores were probably brushed off from 

 normal or diseased bark, or both, by the movements of the in- 

 sects over these surfaces. Some were probably obtained while 

 eating the pustules, and some may have been obtained from the 

 soil around the bases of diseased trees. 



16. Most of the insects were also carrying spores of fungi 

 other than Eniothia parasitica. The number of species of 

 other fungi varied from 0 to 7 in the cultures, but was shown 

 by microscopic examination of the centrifuged sediments to 

 be greater in at least some cases. 



17. In proportion to size, insects may carry a greater 

 number of spores of the blight fungus than birds. 



18. We are led to the conclusion that some insects carry 

 a large number of spores of the blight fungus, and that they 

 are important agents in the local dissemination of this dis- 

 ease. This is especially true of the beetle, Leptostylus macula. 



LITERATURE CITED. 



J. Allard, H. A. The mosaic disease of tobacco. Bui. U. S. 

 Dept. Agr. 40: 1-33. 1914. 



2. Anderson, P. J. and Babcock, D. 0. Field studies on 

 the dissemination and growth of the chestnut blight fungus. 

 Bui. Pa. Chestnut Tree Blight Commission 3: 1-45. 1913. 



3. Bary, A. de. Comparative morphology and biology of 

 the fungi, mycetozoa, and bacteria. Translated by H. E. F. 

 Garnsey; revised by I. B. Balfour. 525 pp. 1887. The Claren- 

 don Press, Oxford. 



4. Berlese, Amedeo. Rapporti f ra la vite ed i Saccaromiceti. 

 Ricerche sui mezzi di trasporto dei fermenti alcoolici. Rivista 

 di Patologia Vegetale 5: 295-340. 1897. Reviewed by Giglioli, 

 I. Insects and yeasts. Nature 56: 575-577. 1897. 



