100 



MOSSES AND FERNS 



CHAP. 



and these lobes, according to Leitgeb's view, are very simple 

 leaves. In Fossombronia (Fig. 41, C, D), while the general 

 thallose form is more or less evident, the leaves are unmistak- 

 able, and as their development shows, morphologically the 

 same as the leaves of the acrogynous forms. The most re- 

 markable form, however, is Treubia insignis, a very large 

 foliose Liverwort discovered by Goebel in Java. This has all 

 the appearance of a very large acrogynous form, and also the 



typical three-sided apical 

 cell; but in regard to the 

 position of the sexual or- 

 gans it is typically ana- 

 crogynous. These and the 

 Haplomitriese form a per- 

 fect transition from the 

 Anacrogynse to the Acro- 

 gynse. 



The multicellular gem- 

 mae of Blasia have been al- 

 luded to. They are pro- 

 duced in long flask-shaped 

 receptacles, and when ma- 

 ture forrn nearly globular 

 brownish bodies whose 

 cells contain much oil, and 

 whose stalk consists of a 

 simple row of cells. Among 

 them are glandular hairs, 

 which secrete mucilage, by 

 the swelling of which the 

 gemmae are loosened from 

 their pedicels, as in Mar- 

 chantia. Similar but sim- 

 pler gemmae having usually 

 three cells occur in Treubia 

 (Goebel (13)). Blasia is also characterised by the presence 

 of colonies of Nostoc within the thallus. These occupy cavi- 

 ties in the bases of the leaves and are normally always present. 



The Haplomitriece 

 The two genera, Haplomitrium and Calobryum, which con- 



B 



Fig. 48. — A, Young plant of Aneura palmata 



X265 (after Leitgeb) ; B, three views of 

 a young plant of Pellia calycina, X420 

 (Leitgeb). 



