1910] Reiff — Resistance of Gypsy Moth Eggs 163 
ment. Fifty-two eggs were found in this excrement and of these 
one hatched on the 23rd of March, followed by two on the morning 
of the 24th. A later investigation showed fully developed cater- 
pillars in the eggs which had failed to hatch. 
Screech Owl. 
I at first attempted to feed the owl on bits of chopped beef in 
which eggs had been placed but it refused to partake of this mixture. 
It was then allowed to fast for a couple of days after which I offered 
it a freshly killed mouse into which one hundred and twenty dispar 
eggs had been placed through an incision made in the abdomen. 
This prepared mouse was given to the bird late one afternoon and 
was eaten during the following night. Late the next afternoon I 
found the red colored vomitings composed of the indigestible parts 
of the mouse and these contained a considerable number of dispar 
eggs, although none could be detected in the excrement. Altogether 
I found one hundred and twelve eggs, every one without any sign 
of injury. At the same time that the control eggs began to hatch 
some of those obtained from the owl gave forth caterpillars until 
altogether seven appeared. All of the others failed to hatch 
although they changed color in a normal way. 
Carrier Pigeon. 
This bird was fed upon a mixture of boiled pigeon-food to which 
the Gypsy Moth eggs were added. This was given to the pigeon late 
in the morning and after three hours had passed through its ali- 
mentary tract. Quite a number of eggs had been eaten by the 
pigeon but none was found in the excrement. 
To sum up the details of these various experiments it is seen that 
Gypsy Moth eggs can withstand the action of the digestive fluids 
of birds belonging to at least two families, Turdide and Bubonide, 
without suffering any, or only slight, injury. In regard to the large 
family, Fringillide, also an insectivorous group, I am inclined to 
believe that these birds might also occasionally distribute Gypsy 
Moth eggs in spite of the negative results obtained in my experi- 
ments. Since the members of the pigeon family grind up their food 
in a gizzard filled with small stones it is very unlikely that Gypsy 
