346 JOURNAL OP ECONOMIC ENTOMOLOGY [Vol. 3 



eggs or 22 per cent, still remained in the gizzard of the three sparrows 

 after death. Twelve of these were intact, while the remainder con- 

 sisted of various sized pieces of chorion. 



Many of the eggs that were found whole in the excrement con- 

 tained large wrinkles. This was undoubtedly the result of the grind- 

 ing and pressure the eggs received while passing through the gizzard. 

 This organ is very muscular and by its contraction and expansion, 

 assisted by the gastric juices, has a tendency to crush all contents. 

 Undoubtedly most of the 135 eggs passed intact, which did not hatch, 

 were injured in passing through this organ. 



Experiment in Feeding a Pigeon 



A female pigeon was secured February 26 and encaged in a box 

 12 X 12 X 18 inches. Cracked corn and dough containing P. dispar 

 eggs were placed in the cage during the first day, but the pigeon did 

 not partake of either. It appeared very lonely and inactive, which 

 was perhaps due to being separated from its mate. As it did not take 

 food voluntarily, it was removed from the cage twice daily, and egg 

 and dough mixture forced into the beak. About 200 eggs were given 

 each time. The excrement was removed from the cage after each 

 voidance, and carefully examined, yet it revealed no eggs intact. 

 They were well ground in every case, leaving no parts distinguishable, 

 save the small particles of chorion. The pigeon was fed for the last 

 time at 8.15 a. m., March 2, and killed at 6 p. m. of the same day. 

 No excrement was found in the cage after the morning feeding. 

 Three hundred and fifty-five eggs intact and some meal were found 

 in the crop. One hundred and seventy-eight and fragments of 22 

 others were removed from the gizzard. This indicates the slowness 

 and thoroughness with which the pigeon digests its food. The vitality 

 of gypsy moth eggs is totally destroyed after having been subjected 

 to such a grinding process. 



In concluding, it must be borne in mind that these experiments 

 were conducted under abnormal conditions. The birds were not only 

 forced to swallow the food, but were deprived of their freedom, which 

 is essential to rapid and vigorous digestion. To procure the data 

 obtained would have been difficult in the field, as it would have neces- 

 sitated, long and careful watches and the killing of many useful 

 species. It would have been impossible to find the voided excrements 

 desirable. However, there remains a field open to investigation for 

 accurate notes on species of birds liable to eat the eggs of P. dispar, 

 and the condition of the latter when recovered in the excrement under 

 normal conditions. 



