CONTROL OF DECAY IN PULP AND PULP WOOD 53 
ammonium nitrate and monobasic potassium phosphate were dis- 
solved in the ratio 100: 0.05: 0.50; for inoculation, soil or liumus 
was used, or the dishes were exposed to the air. The species were 
then separated on malt gelatin and tested for their cellulose-ferment- 
ing ability. Many active cellulose destroyers were thus obtained. 
In order to determine the abundance of mold spores in the air, Van 
Iterson exposed in the garden for 12 hours a Petri dish having a 
surface of 275 square centimeters- and containing moistened filter 
paper. One hundred and fifty-two mold colonies developed, repre- 
senting 35 different species. Fifteen cellulose destroyers in all were 
isolated and described in the course of this first investigation. 
McBeth and Scales (16) list 16 different species as being able to 
destroy cellulose more or less rapidly, and point out that fungi are 
not so largely confined to acid soils as is generally believed. They 
hold that cellulose destruction in soil is largely due to the work of 
filamentous fungi. 
Hartig (9) and a large number of other workers have recognized 
the part that the higher fungi, the hymenomycetes, which we com- 
monly call wood-destroying fungi, play in the destruction of cellulose 
and other constituents of wood. 
Of the fungi which infect wood pulp, however, very few investiga- 
tions have heretofore been made, although notes concerning the 
deterioration of paper date back to the early part of the eighteenth 
century. At that time, and until recently, the spotting of paper was 
attributed to the work of larvae. 
In 1896 Klemm in Germany (14), published a short paper in which 
it is stated that the most common, as well as the most detrimental, 
of pulp-inhabiting fungi is RJiyncJiospJtaeria sp. This mold is re- 
ported as appearing either as brown or dark-green spots with dark 
centers from which radiate delicate branched threads, or as numerous 
spots grouped together in blotches or in parallel lines of a gray color. 
Klemm attributed the uneven distribution to the mode of infection. 
This fungus, he showed, is propagated by two kinds of spores — 
ascospores, produced in asci (sacs) in perithecia, minute flask-shaped 
bodies with long narrow necks; and dark colored cells (chlamydos- 
pores) produced in chains in the mycelium. Chlamydospores are by 
far the more common. The perithecia were seen only occasionally 
on the surface of old pulp. 
Klemm pointed out, also, that some organisms, although very 
destructive, are difficult to detect because they produce no discolora- 
tion. Pulp thus infected produces a paper which may rapidly 
become weak and brittle. It is quite evident that these fungi are 
the true wood destroyers, hymenomycetes, but Klemm did not seem 
to recognize them as such. He noted that StacJiybotrys atra Cda., a 
"sooty" mold, is frequently present in large quantities, and that its 
spores cause a perceptible darkening of the pulp. Mention is made 
also of a mold, found on old pulp, which forms small, black, globe- 
like bodies surrounded by a yellow or brown spot. The conclusion 
is reached, however, that both this mold and StacJiybotrys atra are 
relatively harmless, since their mycelia do not pierce, but only inter- 
lace, the wood fibers. 
Barnes (2) , while working as chemist for a large paper mill, observed 
mechanical wood pulp which was seriously damaged by rot — some 
of it rendered 20 to 25 per cent soluble in water and utterly ruined. 
