ete aes ReO UN Beeb bebe Len. 11 
Freshly discovered points of infection were mapped last year in Penn- 
sylvania, Ohio, Arkansas, Nebraska, and Kansas. The disease also was 
found to be spreading actively in southern Missouri. 
Neither the agent which spreads the disease nor its cure has yet been 
discovered by scientists, although many of them are working overtime on 
these jobs. Until the manner by which the fungus spores are spread is 
discovered, there is little that can be done to control the disease. It is 
known that local spreading takes place through natural root grafts between 
neighboring trees, but this does not account for the broad leaps from west- 
ern Indiana to central Ohio to central Pennsylvania which are indicated on 
the distribution map of the blight. Neither does the pattern of spread hint 
at windborne spores. Many believe that some insect, bird, or rodent may 
be the host. To date only the prompt cutting and removal of diseased trees 
can be recommended. Where valuable shade trees are involved, ditching 
to sever the interlocking root systems between infected and healthy trees 
has been used. 
Fortunately, there is no indication to date that oak wilt is developing 
anything like the whirlwind momentum attained by the chestnut blight 
that swept like a forest fire through every stand of chestnut in the United 
States during the second decade of the century. The more gradual and 
sporadic spread of the disease, coupled with advances in forest research, 
give substantial hope that a control method may yet be devised. Much de- 
pends, however, upon the funds and manpower made available to the still 
underfinanced and understaffed forest research laboratories at both state 
and federal levels which, together, share a monumental task. 
715 South Division Street, Barrington, Illinois 
put fT Fl 
Audubon Screen Tours for 1951-52 
THE ILLINOIS AUDUBON SOCIETY will again present a series of five illus- 
trated lectures on natural history this winter. As before, outstanding 
American ornithologists will speak on a variety of subjects. The tentative 
schedule of lectures is as follows: 
Ganda eNG ue! tatrangw. “Fialllonkl hes Four Goriers 
Saturday, Jan. 26: Lucie Palmer on Underwater Kingdom. 
Saturday, Feb. 23: Bert Harwell on Canada East. 
Sunday, March 16: Dr. Olin S. Pettingill on Athabaska Sojourn. 
Wednesday, April 23: Howard Oreans on Wildlife at Your Doorstep. 
As before, lectures will be held in the James Simpson Theater of the 
Chicago Natural History Museum, Roosevelt Road and Lake Shore Drive. 
Saturday and Sunday lectures will begin at 2:30 p.m.; the Wednesday 
lecture at 8:00 p.m. Members are reminded to come early to get the best 
seats. Official program announcements will be sent out later this month. 
