The chlamydospores of Ustilago maydis , U. nuda , and Sphacelotheca reiliana were analyzed by gas chromatography and mass spectrometry for their hydrocarbon contents. For the first time we observed that they contain paraffinic hydrocarbons; the average contents were 42, 58, and 146 parts per million, respectively. n -Alkanes having odd numbers of carbon atoms predominate, with carbon-chain lengths ranging from C 14 to C 37 . The major alkanes are n -C 27 in U. maydis , n -C 27 and n -C 35 in U. nuda , and n -C 29 in S. reiliana . Each type of spore carried a distinctly characteristic population of hydrocarbons.