Fine structure of Lichens

Abstract

  Fine structure of two foliose lichens, Parmelia pertusa and Coccocarpia cronia is observed by means of electron microscope.

  The wall of hyphae in the gonidial layer of P. pertusa consists of two layers; the inner layer is electron opaque and the outer one less opaque. In the gonidial layer of these lichens, an association of hyphae with algae is observed. In P. pertusa, association of the inner layer of hyphal wall with the wall of Trebouxia-gonidia is seen, and in C. cronia hyphae are embedding in the sheath of Scytonema-gonidia. Hyphae in the upper cortex of P. pertusa are surrounded by fibrils (Fig. 4).

  Cultured algae isolated from P. pertusa are different from the gonidia in the thallus as follows ; (1) starch grains are seen around the pyrenoid, (2) electron opaque granules occur in the cytoplasm, (3) algal wall is thicker than that in the thallus. (compare Fig. 1 with Fig. 3)