GLOSSARY 447 
Fruit-body. A spore-bearing structure. 
Fusiform. Spindle-shaped. 
Germtube. A tube developed from aspore on germination. It usually 
gives rise directly to mycelium. 
Gill. Plate or lamella of a mushroom, found on the lower side of the 
cap or pileus. 
Haustorium (haustoria). Special mycelial branch sent into the cell 
serving as an organ for obtaining food. 
Heterecious. Said of fungi (usually rusts) requiring more than one 
kind of host-plant on which to complete the life-history. 
Hypertrophy. Abnormal enlargement of a part or the whole of a plant. 
Specifically, the abnormal enlargement of cells. 
Hypha (hyphe). A vegetative or mycelial thread of a fungus. See 
mycelium. 
Infect. To cause disease. 
Infection. Act and condition of being infected. See infect. 
Infection-court. Place where infection is initiated. 
Inoculum. The transferable portion of a pathogene which.may bring 
about infection. , 
Lamella (lamellex). Gills of a mushroom. See gill. 
Lenticel. A specially developed loose cellular structure in the cork 
of a plant through which an exchange of gases between the interior 
of the plant and the air may take place. 
Lesion. Any definitely diseased region. 
Middle-lamella. The primary membrane between any two cells of 
higher plants. 
Morphology. The science which treats of the form, size and color of 
an organism. 
Mycelium. The vegetative system of a fungus made up of hyph» 
or threads. See hypha. 
Oospore. Special type of sexual spore. 
Parasite. An organism which lives in or on another living organism 
during a portion or all of its life for the purpose of obtaining food 
and habitation. The latter organism is referred to as a host. 
A parasite is usually smaller than its host. 
Pathogene. A disease-producing factor, usually an organism. 
Pedicel. A fruit-bearing or flower-bearing stalk. 
Peduncle. A general stalk bearing a group of flowers or fruits. May 
bear but one flower or fruit. 
Perennial. Lasting more than two years. 
Perithecium (perithecia). Closed globose or flask-shaped, sexual fruit- 
body containing asci. Finally a small opening or pore may appear 
at the top. See apothecium. 
Petal. The inner row of flower leaves, usually white or colored other 
than green. 
