STRUCTURE OF FUNGI. 47 



tions of species in the former group — is formed, seems at first 

 sight totally different from that of other Fungi, But the gra- 

 dations arc very gentle, and every intermediate condition may 

 be found. In these as much as in the Fungi of the primary 

 group, there is a distinction of spawn and fruit, though the 

 diiference is in this case even more highly exaggerated, espe- 

 cially in those instances where a distinct receptacle occurs, 

 in which the perithecia are lodged, as in Xylaria (Plate 24, 

 fig. 1, 2), and Cordiceps (Plate 23, fig. 4, 5, 6, 7). 



Beside the general tissue of which Fungi are composed, in 

 a few species, as the Lactarii (Plate 13, fig. 2, 3, 4), or milky 

 Agarics, there are distinct vessels like the vessels of the latex 

 in pha^nogams, which contain a milky fluid. They exist in 

 all parts of the plant, especially in the gills, where they part 

 with their contents on the slightest touch. This fluid is of 

 various colours, mild or extremely acrid, and often changes 

 colour when exposed to the air. When dry it forms an unc- 

 tuous mass, which burns with a brilliant flame. In some 

 Russulae (Plate 13, fig. 5, 6, 7, 8), though probably not in the 

 species represented in the Plate, these vessels exist, but con- 

 tain a watery fluid only. 



In many Fungi, something at first sight quite distinct from 

 the cellular tissue seems to exist, in the shape of a viscid fluid 

 which clothes the surface, or which occupies in a more or less 

 condensed form portions of the plant. In every case, however, 

 in which I have examined this under the microscope, the 

 slime appears to be formed of extremely delicate gelatinous 

 threads, while the firmer gelatine is formed cither of similar 

 threads or of threads with extremely thick external walls and 

 a very slender cavity. 



The soft pulpy mass of which the Myxogastrcs are com- 

 posed, destitute as it is of cells, and hardening into threads 

 and peridia equally destitute apparently of organic structure, 



