Gall tumor gall, cecidium
Gall (tumor) gall, cecidium refers to other parasitic organisms, very little is due to symbiotic plant caused by abnormal development or abnormal part of the growth. Mainly due to parasites of the host cell metabolites caused by the abnormal growth (division, hypertrophy, differentiation), sometimes as a result of the collapse of local organizations formed. The past, merely to take note of gall tumor is caused by insects (gall). However, Thomas (1873) it expanded the definition. Sometimes gall tumorigenicity and tar substances and other plants of tumor (plant tumor) caused by parasitic or bacterial inflammation is not easy to distinguish, but the gall tumor tissue generally longer survival time, instead of the original organization in almost no significant differences in life expectancy, it is can be distinguished from the. Can be classified according to the type of host animal gall (Zoocecidium; Germany Zoocecidie) and plant galls (phy-tocecidium; Germany Phytocecidie) two kinds, the former in addition to nematodes, mites ticks, the majority of insects, which in addition to bacteria other than fungi less. Symbiosis with rhizobia and form nodules of leguminous plants also belong to this category.