1921] SPENCER—BRAZIL NUTS 279 
Cephalosporium bertholletianum, n. sp.—Conidiophores hya- 
line, simple or dichotomously branched, 50-90 p long, 2- to 4-septate; 
spore mass globular; conidia hyaline, unicellular, oblong-elliptical, 
guttulate, 6-12 X3.5—5 wu, ends obtuse. 
Hasitat.—On radicle of seed of Bertholletia nobilis Miers and 
B. excelsa Humb. and Bonpl., causing decay. 
3. DRY ROT 
GENERAL DESCRIPTION.—The shell of the nut affected by dry 
rot is mottled, but of somewhat lighter shade in its darkest areas 
than the shells of normal nuts, and the weight is much below normal. 
The cracked shell appears to be filled with a kernel which adheres 
more closely to the shell than is usual, but which is so similar in 
color and general appearance to that of sound nut kernels that it 
might easily pass casual observation as such, although in reality 
it is merely a mass of mycelium. Small pieces of mycelium taken 
from this mass swell to approximately twice their size when placed 
in water. Under the microscope the hyphae were seen to be 
irregularly branched and septate. No conidiophores were seen, 
but what appeared to be unicellular elongated conidia of greatly 
varying length were occasionally found. 
MorpHoLocy.—The hyphae which make up both the aerial 
and the submerged mycelium are irregularly branched, and more 
or less constricted at the septa. The cells are 14-90 u long by 
3-5-11 pw wide, hyaline with granular contents and guttulae (fig. 44). 
Anastomosis frequently occurs, especially in older thalli, when 
spores falling on the medium germinate, producing a tube which 
unites with the cell of an older hypha, another germ tube, or an- 
other spore (figs. 29, 48). 
The simple conidiophores are borne at any place along the 
hyphal strand, seldom more than two being produced by a single 
cell. Branched conidiophores are rare. Thalli resulting from 
direct planting of mycelium taken from the diseased nut produce 
but few conidiophores, and rarely more than single-celled conidia. 
Conidia from transferred cultures are from 1- to 8-celled, sub- 
cylindrical, slightly sickle-shaped, without pedicel, and conical 
at base (fig. 42). 
