Fu.. 12. — Abnormal enlargement of the hyaline cell of an ascospore. The halo 

 about the spore and the hyaline tip of the germ tube is formed by the gelatinous 

 sheath. (X 2250; 



time spore traps were collected. The instruments were placed at 

 ground level in screened shelters, and located near the infected 

 trees used in the spore-trapping experiments. 



Clean, labeled, glass microscope slides were coated with a thin 

 layer of vaseline petroleum jelly. Twelve slides, three per tree, on 

 four infected trees per area, were exposed each week. These slides 

 were attached in vertical and horizontal planes at various heights 

 among infected blanches of diseased trees. Such spore traps were 

 maintained at Camden from May 15 to July 31, and at Cortland 

 from May 28 to August 27, in 1956. These slides were plated no 

 higher than four feet above the ground, since the incidence of 

 Rhabdocline needle cast is greater on the lower portions of the tree. 



A rectangular cover slip was placed over the vaselined surface of 

 each slide at the end of the weekly exposure period. Replacements 

 were set in the same positions among the branches and exposed slides 

 were taken to the laboratory lor examination. The unique dumbbell 



35 



