744 Report oF THE ENTOMOLOGIST OF THE 
bouillon culture of August 14 was used. It was applied full 
strength to the leaves in a fine spray, allowed to dry and then six 
larvae of Pierzs were placed on the sprayed cabbage. On Septem- 
ber 20 only two of the larvee had died apparently from the dis- 
ease; the rest had pupated. .An experiment parallel with this 
was made by applying the spray to the leaves of the cabbage 
while the larvee were on the plant. Of the six larve so treated 
only one died with symptoms of the disease; one was killed by 
parasites and the rest pupated. Two checks were carried with 
the above tests in each of which several died from parasites and 
the rest pupated. No further attempts at artificial inoculation 
were made after this date as no fields were found where a few 
diseased worms could not be obtained. In the last experiments 
i is probable that either the bouillon culture had lost its virulence 
or had become contaminated by other germs. The laboratory 
was not fitted for such work so it was next to impossible to keep 
pure cultures. . 
As previously stated the reasons that no positive, direct proof 
of the contagious character of the disease has yet been obtained 
are: 1st. The difficulty of carrying the disease on culture media 
and retaining its virulence over winter. 2d. The difficulty of 
obtaining healthy caterpillars to treat after cultures of the disease 
were obtained. It is to be hoped that a trial with the disease may 
be made on Long Island with the first brood on early cabbage, 
before it gets started in the fields. In fact, this will be the only 
way of making field tests of the disease. If it should prove a 
success it would be necessary to test the germ thoroughly on 
higher animals before it can be recommended for general use. Of 
course we have a partial test of this from the fact that germs of 
the disease have been on cabbage for the past 10 years and prob- © 
ably longer. No ill effect could result from thoroughly cooked 
cabbage. Like all diseases and parasites it can only act as a 
check to the increase of the cabbage butterfly. 
Conclusions. Care should be used not to destroy the para- 
sites of the cabbage caterpillar, yet it should be remembered that 
these act merely as checks to their increase and can not be ex- 
pected to exterminate them. 
Preventive measures are worth more than all the named reme- 
dies, although applied at one time. If capturing is not practical, 
