[ 305 
XIII. On G aster olichenes : a New Type of the group Lichenes. 
By George Massee. 
Communicated by W. T. Thiselton Dyer, M.A., C.M.G., F.R.S., Director , Royal 
Gardens, Kew. 
Received May 5,—Read June 16, 1887. 
[Plate 25.] 
Until recently the time-honoured division of Thallogens into three primary groups, 
Algae, Fungi, and Lichenes, was retained, the most prominent morphological features 
of the last group consisting in the vegetative portion being composed of slender 
achlorophyllose threads mixed with chlorophyll-producing cells or gonidia, and the 
spores produced in asci. It was assumed that the gonidia were in organic continuity 
with the colourless threads, an assumption challenged by Sch wendener, who con¬ 
siders a lichen as a combination of a fungus and an alga, an idea now widely enter¬ 
tained, nevertheless, curiously enough, numbering amongst its opponents most of the 
leading lichenologists and mycologists of the day, most of whom, it is important to 
remember, are distinguished as systematists rather than as biologists. Later researches 
have placed almost beyond doubt the truth of Schwendener’s theory. BornetI has 
shown that in numerous instances the gonidia can with certainty be referred to some 
species of Algae, and further succeeded in building up a lichen synthetically by sowing 
the spores of Rarmelia parietina upon Protococcus. Stahl]; also, by growing the 
spores and gonidia ( pleurococcus ) of Endoccvrpon pusillum, produced the lichen which 
bore perithecia and spermogonia. The same author has also demonstrated the 
presence of sexual organs of reproduction in a gelatinous lichen, Collema micro- 
phyllum, the female portion resembling the carpogonium, with its trichogyne, met with 
in the Floriclece. Spermatia, produced in the spermogonia, are the fertilising elements. 
The discovery by Mattirolo § of a second type of lichen structure, Hymenoliclienes, 
characterised by having the spores borne on basidia, the latter compacted into a 
* “ Untersucbungen iiber den Fleclitenthallus,” in Nageli’s ‘ Beitrage znr Wissenscb. Botanik,’ 1860, 
1862, and 1868. See also ‘Flora,’ vol. 55, 1872 (Nos. 11-15). 
t “ Reclierckes sur les Gonidies des Lictiens,” ‘Ann. Sci. Nat. (Rot.),’ vol. 17, 1873. 
+ 1 Beitr. zur Entwickel.-Gescli. der Flecliten,’ 1877. 
§ “ Contribuzioni alio Studio del genere Cora, Fr..” ‘ Nuovo Giorn. Botan. Ital.,’ vol. 13, 1881, p. 24-5. 
(2 plates.) See also “ Die Gruppe der Hymenolicbenen,” Fried. JohoW. ‘ Pringskeim, Jabrb. Botan.,’ 
vol. 15, p. 361. (5 plates.) 
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