A text-book of mycology and plant pathology / by John W. Harshberger.

  • Harshberger, John W. (John William), 1869-1929.
Date:
1918, [©1917]
Catalogue details

Licence: Public Domain Mark

Credit: A text-book of mycology and plant pathology / by John W. Harshberger. Source: Wellcome Collection.

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    is snow-white; later it becomes reddish brown. The discovery of perithecia is yet to be made. Aspergillus Jlavus plays an important part in the cocoon disease of silkworms. The stipe portion of its conidiophore is roughened by colorless granules. Aspergillus luchuensis, according to Inui, is used in the preparation of a beverage Awamori, which resembles whisky and is used in the Loochoo islands. Aspergillus lokelau is found in Tokelau, or Samoan disease, attack- ing the natives of certain of the Pacific islands. An important patho- genic species, which causes an epidemic disease of pigeons and lives in the human ear and the lungs of various birds, is Aspergillus fumigatus, which was the cause of a false tuberculosis of a calf in Philadelphia. An autopsy by Ravenel and the writer showed the lung tissue of the calf penetrated by the mycelial hyphae of the fungus, and its conidio- phores bearing the conidiospores in a fan-like manner were seen project- ing into the lung cavities almost completely filling them. It, therefore, grows well at blood temperature, and if its conidiospores are introduced into the arterial circulation of animals they germinate and produce serious illness, which may terminate fatally. It also acts injuriously in certain fermentation processes carried on at high temperatures as certain lactic acid fermentations. It attacks tobacco, decaying potatoes, bread, malt and beerwort. It has dwarf conidiophores 0.1 to 0.3 mm. long, with club-shaped globules 10 to 20/x thick, upright sterigmata 6 to 15/x long and with long chains of conidiospores (2 to 3^). Nut-brown globular perithecia are found, 250 to 350/z in diameter, in- closing oval thin-skinned asci (9 to i4ju) with eight red lenticular tough- walled spores (4 to 4.5/z). As a parasite of the human skin it was called Lepidophyton. The green mould, which usually grows on malt, is Aspergillus clavatus causing a moulding of the substratum. The largest species of the group is Aspergillus giganteus, which looks at first super- ficially like a Mucor, but later owing to its grayish-green conidiospores it is readily separable from the mucor vegetation. Its sterigmata seem to be hollow, communicating with a pore-like opening with the center of the conidiophore. No perithecia have been found. Other species are A. nidulans (Fig. 50), which can be cultivated readily, A. various and A. ostianus, the latter distinguished by an ochraceous pigment. The black mould Aspergillus niger more properly Sterigmatocystis niger