APPENDIX 367 



Protoplasm. Living substance within the cells of plants and animals. 

 The seat of growth and many other functions which are charac- 

 teristic of living things. 



F'ycnidium (pycnidia). An inclosed globose or flask-shaped fruit- 

 ing-body containing simple asexual spores. 



Rhizomorph. A compact bundle of myceUum arranged parallel to 

 form a root-like structure. See shoe-string root-rot, page 78. 



Saprophyte. A Uving organism which obtains its food-materials 

 from dead organic material. See Parasite. 



Sapwood. The wood between the heartwood and bark. Sapwood 

 contains living cells and is the tissue which is active in translo- 

 cating food-materials to aU parts of the tree. 



Sclerotium (selerotia). A compact, more or less globose structure 

 made of closely aggregated myceUum. Usually a resting body 

 rich in stored food. 



Spore. A portion of the mycelium which is detached and serves as 

 a propagative or reproductive body, corresponding to the seeds 

 of higher plants. Spores may be formed sexually or asexuaUy. 



Stomate. SpeciaUzed structures with an opening in the center, found 

 on the surface of leaves. Stomates open and close and regulate 

 the exchange of gases and water vapor between the interior of 

 the leaf and the surrounding atmosphere. 



Stroma (stromata). Compact aggregation of mycelium forming a 

 fungous layer. Fruiting-bodies may be formed imbedded in the 

 stroma. 



Teliospore. A type of spore formed by the rust-fungi. AU rust- 

 fungi form teliospores and basidiospores. They may omit any 

 one or all of the other stages. TeUospores in many species over- 

 winter. When they germinate they form basidiospores directly. 



Urediniospore. A type of spore formed by the rust-fungi. These 

 spores are produced in summer and serve to distribute the fungus 

 rapidly during the growing season. Urediniospores are usually 

 produced from mycelium that originated from seciospore infec- 

 tion. Later teliospores are formed from the same mycelium. 



General Bibuography op Tree Diseases 

 American Publications 



Atkinson, G. F. Studies of some shade tree and timber destroying 



fungi. Cornell Univ. Agr. Exp. Sta. Bui. 193 : 199-235, figs. 



66-94. 1901. 

 Cook, M. T. Diseases of shade and forest trees. In The planting 



and care of shade trees. Forest Park Reservation Commission 



of New Jersey, pp. 93-124, flgs. 36-43. 1912. 



