10 
length of time they will remain alive, but will be stunted. 
Sand dries out rapidly, and if not kept constantly moist 
the seedlings will be lost at the critical time of germina- 
tion. Seedlings that have germinated and whose roots 
extend down about an inch will not. suffer if the surface 
sand becomes dry.’ However, extremely fine seed that are 
very near the surface might just be germinating when 
the surface dries out, and if the sun is shining they will 
be lost in a short time. Aside from the two main objec- 
tions to sand as a germinating medium—lack of food and 
the rapidity with which it dries out—it has so many good 
qualities that it cannot be overlooked as a material in 
which to sow seed. 
Seedlings are always subject to the ravages of the 
damping-off disease. This disease can attack a crop of 
seedlings and destroy them over night. Figure 1, plate 
13, gives a good illustration of the nature of the disease 
and its work. The thread-like structure of the parasite 
spreads over the surface of the soil and attacks the seed- 
lings. The illustration referred to shows zinnia seedlings 
in various stages of the attack. The first one has threads 
of the mycelium around its base; the second and third 
have already lost their roots; and the fourth seedling has 
completely collapsed. This disease is always associated 
with a great amount of humidity, and on that account 
seedlings or seed boxes in which the seed are just ger- 
minating should never be watered toward evening. The 
surface of the pots or boxes should be dry at night, 
because it is at that time this disease is most active. If 
seed are sown in sand instead of soil there is much less 
danger from attacks of the damping-off disease. One of 
the chief reasons why sand is so much better than soil for 
sowing seed is that it does not retain as much moisture 
as soil, even though it is watered more frequently. Seed- 
lings will be lost by the damping-off disease, even if sown 
in sand, if the seed are crowded or if the air about the 
seedlings is very humid. This humid condition can easily 
be created if the cover glass or paper is left on the boxes 
or pots after the seedlings are up. 
PUDOR’S, INC., PUYALLUP, WASH. 
