ENDOTHIA PARASITICA AND RELATED SPECIES, 25 
capable of absorption, a power which it retains relatively perma- 
nently.” In addition to its absorptive function the entostroma forms 
the pseudoparenchymatic cover for the perithecial walls. 
Ruhland studied herbarium material from the Royal Botanic Mu- 
seum of Berlin and specimens from Saccardo and Cesati, and de- 
scribed it under the name of Endothia radicalis (Schw.) Fr. (Z. 
fluens of the present writers). He distinguishes an ectostroma, 
shaped like a truncated cone, consisting of fine, thin-walled hyphe, 
so closely interwoven that the whole structure has a comparatively 
firm quality. Among these hyphe are crystals of calcium oxalate. 
As soon as this ectostroma breaks through the bark there is formed 
near the middle a short-lived 1-chambered pycrtidium. Below this 
ectostroma (height 0.5 to 0.6 mm., diameter 0.7 to 1 mm.) the ento- 
stroma grows out as a mycelium through the upper portion of the 
bark. Ruhland says, “'The entostroma with us does not produce per- 
ithecia, but remains wholly mycelial.” He studied the perithecial 
stage in Cesati’s specimens, however, and concludes that the peri- 
thecia originate without much change in the size of the entostroma 
and at a considerable distance, about 1 mm., below the ectostroma. 
The long necks then penetrate through the overlying entostroma 
and into the ectostroma to the base of the now functionless pycnidia. 
The upper portion of the ectostroma is then quickly killed and 
thrown off. 
Pantanelli briefiy described the stromata of the genus Endothia, 
and pointed out several morphological characters which he considers 
distinctive of FE’. parasitica in contrast to EL’. fluens. Aside from spore 
characters, which will be discussed later, Pantanelli (60, p. 870) con- 
siders that EZ’. parasitica is characterized by numerous stromata, at 
first embedded in the bark, finally free; by pycnidial cavities numer- 
ous and irregularly arranged in various planes in the stromata deep 
in the bark; pycnidial stromata 1.1 to 1.2 mm. in height and 2.1 to 2.2 
mm. in diameter; ascogenous stromata, height 1.8 to 2 mm., length 
2.5 to 3.4; width, 3 to 3.2 mm.; perithecia arranged in two or three 
layers; necks of perithecia averaging 1.25 mm., with inconspicuous 
ostioles; walls of the perithecia uncolored or light brown. 
Endothia fluens, on the other hand, has isolated stromata, chiefly 
outside the bark; pycnidia aggregated, regularly arranged in a single 
superficial series; pycnidial stromata, height 0.4 to 0.5 mm., diameter 
1.1 to 1.3 mm.; ascogenous stromata, height 1.1 to 14 mm., length 
2.5 to 3.2 mm., width 1.2 mm.; perithecia arranged in a single row; 
necks of perithecia averaging 0.45 mm.; ostioles prominent; walls 
of the perithecia black. = 
Anderson (1, pp. 17-24) described the development of the fructifi- 
cations of Endothia parasitica in detail. He studied the growth of 
