1915] Scverin, Severiii and Ilartung — Leaf-ori positing Tacliinidw 135 



tated from the mid-intestine into the fore-intestine in the cater- 

 pillars used in the previous experunent, a host was selected which 

 did not exude a liquid from the mouth when handled. Several 

 mature, male walking-sticks (Diapheromera femorata Say) were fed 

 bits of hazel-nut leaves upon which the eggs of a leaf-ovipositing 

 tachinid (Phasmophaga antennalis Towns.) were glued. Each of 

 two walking-sticks, which had swallowed twelve eggs of the 

 parasitic fly, was injected with 95 per cent, alcohol three hours 

 after feeding and was then dissected. All of the eggs were found in 

 the fore-intestine at some distance in front of the oesophageal 

 valve but not one of the eggs had hatched. Another specimen, 

 which had swallowed seventeen eggs, was dissected five hours after 

 feeding. In this case, nine eggs were found in the posterior region 

 of the fore-intestine but none of these had hatched ; eight eggs were 

 taken out of the mid-intestine in the region of the glandular appen- 

 dages and seven had hatched. Only one larva was found within 

 the contents of the mid-intestine. Upon clearing and mounting 

 the entire contents of the abdomen, it was found that six maggots 

 had bored through the mid-intestine; four of these were embedded 

 in the fat tissue of the body wall and two were found in the testes. 



The question naturally suggested itself, will the eggs of Chceto- 

 gccdia monticola hatch in an acid liquid regurgitated from the mouth 

 of an insect .f* The liquid ejected from the mouth of a katydid 

 gave an acid reaction, and eggs were emersed in this medium. A 

 few minutes later one of the eggs hatched. 



The blood of army worms was extracted and gave an acid re- 

 action. From one hundred eggs emersed in this liquid, forty-five 

 larvse emerged. Of thirty -five eggs placed in the blood of the 

 caterpillar of the milkweed butterfly only two hatched. It is 

 evident than many eggs failed to hatch in the various acid media. 



In another experiment the eggs of Chtetogsedia were emersed in 

 the acid juices pressed from blades of grass upon which the Qj 

 deposited its eggs, but not one of the eggs hatched. 



x\n attempt was made to hatch the eggs in a weak, alkaline so- 

 lution of sodium hydroxide. After experimenting with a number 

 of formulas it was found that 100 eggs emersed in a .1 per cent, 

 solution of sodium hydroxide, eighty-fi^e hatched and of the same 

 number of eggs emersed in a .05 per cent, solution of sodium hy- 

 droxide seventy-two hatched. After the eggs had been emersed 



