Annual Report of the 
456 
WINTER MULCH. 
If from a short rain-fall in autumn, the tree soil is not well sat¬ 
urated, then you surely need this natural mulch of vegetation to 
insure your trees against this root-killing. A heav}~ winter mulch 
is the only absolute safety in this matter. This will retain 
the frost until it is removed by the warm spring showers.— 
This is especially necessary in southern Wisconsin, as we are be¬ 
low the uniform snow-lines, and yet we have the extreme and pro¬ 
longed cold of winter, the frost remaining a solid mass, at ten to 
twenty inches depth, while the surface may be dried out by the 
warm sun and south winds of March. This snow-line spoken of is 
the point where the snow falls early, and remains through the winter 
until the spring rains. It varies with the seasons, sometimes ex¬ 
tending below the south line of the state, and almost uniformally to 
the latitude of Portage, and the lines of the Wisconsin River below 
that point. Hence, root-killing is the most prevailing effect of win¬ 
ter below that line, while it may be almost unknown above that line, 
but top-killing will be the more common, especially on the richer 
soils which produce a late growth of wood. 
INSECTS AND VERMIN. 
Here opens a wide and inexhaustible field of observation and re¬ 
search, and one well traversed bv but few of the most studious and 
observing. It is one to which lives of toil have been given, and on 
which volumes have been written, and to any, whose task and time will 
admit, I commend these works as worthy of careful study, and the 
field as one rich in good to our race. But its paths are intricate, of¬ 
ten very obscure, and no especial halo of glory lightens the plod¬ 
ding way of the entomologist. 
But as the name Agassiz inspires enthusiasm in the student of 
zoology, so may the memory of a Walsh, and the labors of Fitch, 
Riley and Le Baron be better appreciated and similar laudable efforts 
be encouraged by substantial aid from the state. We need to know 
more of the habits of the insects that prey upon our fruits and 
other products of the farm. Entomology is to-day one of the sub¬ 
stantial departments of natural history, but its study is a labor 
which requires the time and careful investigation of the best minds, 
and we trust the time is not far distant when the farmers of the 
West will see it for their interest to encourage such efforts by re¬ 
wards in some way commensurate with the value of this labor. 
