410 DIVISION III—-MODE OF LIFE OF THE FUNGI, 
and in Sticta, and Seytonema or Stigonema in Stereocaulon. In many forms, for 
example in Sticta and Stereocaulon, the Nostocaceae are localised in peculiarly shaped 
branched or convex outgrowths from the thallus, which have received the name 
of cephalodia. ; 
The Alga is firmly attached to the adjoining hyphae; where the structure is a dense 
pseudo-parenchyma as in Endocarpon it is squeezed in between the hyphae ; where it 
is filamentous and lacunose the hyphae send out branches, which attach themselves 
firmly to the algal cells ; it not unfrequently happens that the hypha comes into contact 
with the new cells formed by division of the algal cells, and in that case it sends out 
small branches from the point of contact which embrace the Alga closely in the way 
A 







FIG. 175. Thelidii ‘9 di A perithecium on the thallus; 2 groups of Algae, FiG. 176. vw—d Cystocoleus ebe- 
m the part of the thallus without Algae spreading in the 2 the peritheci neus, Thw. a extremity of a branch 
cut through the middle, represented diagrammatically and slightly magnified. 3 a group seen from without. 5 a similar one 
of Algae with hyphae growing round them, magn. 480 times. After Stahl. in optical longitudinal section ; x the 
Algae; a and 4 from preparations 
made transparent by Schulze's solu- 
tion. ¢, @ transverse sections, 
e, / Coenogonium Linkit, Ehrb.; 
e slender branch of the thallus with a 
ateral branch in optical longitudinal 
section. transverse section through 
a stronger branch. After Schwen- 
dener. a, 4, ¢, d,¢ magn. 390, / 300 
times. 
described above in the case of germ-tubes (Fig. 167 EZ). The Stigonema which is 
peculiar to the cephalodia of Stereocaulon furcatum is seized by the hyphae in the 
same way as in Ephebe which will be noticed further on. 
2. There are a considerable number of Lichens, which are reckoned in 
descriptive works among the heteromerous species and agree with them on the whole 
in the manner of their growth, but which depart from the scheme of the heteromerous 
thallus in having no differentiation of a rind, and having the Algae scattered among 
the hyphae. Of this kind are the marine fruticose Lichinae which have Calothrix 
scopulorum, Ag. for their Alga’, the frondose Pannarieae with Algae from the groups 
of Nostoc and Scytonema, a large number of Graphideae of different genera, 

! See Kny in Sitzgsber. d. Naturf. Freunde 1874, and Bornet in Ann. d. Sc. Nat. ser. 5, XVII. 
