528 L ewton -Brain. — Cordyceps ophioglossoides (Eh rh). 
* In none of my preparations showing this intercellular net- * 
work was there any sign of intracellular hyphae or of haustoria. 
I may say now that in no case have I ever seen anything 
of the peculiar mulberry-like ingrowths, figured and described 
by Reess. 
The next older stage of this form of the mycorhiza is 
shown in Fig. 26. On the outside is the pseudoparenchy- 
matous fungus-sheath, which has invaded in parts the root- 
tissue — the outer layer of cells of the root is quite broken up, 
leaving only bits of cell-wall surrounded by the fungal network. 
Following this fungus-sheath we get the root-cortex : this no 
longer shows the intercellular network of internal hyphae ; the 
cells are separated by large empty spaces ; they are filled with 
the slimy, dark-staining masses mentioned above. In nearly 
every case the walls of these cortical cells are beginning to 
break down. In the centre of the section we get the feebly 
developed stele, which appears quite healthy and unaffected 
by the Fungus. 
The oldest stages have a very peculiar appearance (Figs. 27, 
28). As before on the outside we get the fungus-sheath quite 
healthy and unchanged. In the centre of the section, also 
healthy and unchanged, is the stele. But between the fungus - 
sheath and the stele we have simply an almost homogeneous 
mass of slimy, disorganized cell-contents, in which we are 
still able sometimes to trace the outlines of the original 
cortical cells. Scattered in this we get broken bits of cell- 
walls and some few nuclei. 
Stahl 1 has recently treated afresh the whole question of 
mycorhiza ; he reviews all previous work and himself supports 
Frank’s view that in all cases the mycorhiza is a symbiotic 
union between the Fungus and the host root. He regards 
the Fungus as the dominant partner, which has forced itself 
on the host by cutting off the food-supply, and so compelling 
the higher plant either to compete with it by means of an 
extensive root and leaf-system, or to submit to an alliance. 
Certainly in the union between Elaphomyces and the Pine 
1 Prings. Jahrb., 1900. 
