EGG PARASITES OF THE GIPSY MOTH. 179 



definitely proved to be primary, was the prime argument which finally 

 resulted in the detachment of Mr. H. S. Smith from the cotton boll 

 weevil investigations and his transfer to the laboratory staff. By 

 the time he was prepared to undertake his new work a large number 

 of eggs from which Anastatus, Tyndarichus, and Pachyneuron were 

 positively known to have issued were ready for dissection and study, 

 and to these were soon added a number from which Schedius was 

 similarly known to have come, secured in the manner about to be 

 described. 



The first Schedius which was ever reared in a living condition 

 issued from an isolated egg in the laboratory in December, 1908. It 

 was a male, and it died before it could be furnished with a mate. 

 The next individual issued on January 8 from an egg which had been 

 isolated on December 19. It was a female, and she was immediately 

 transferred to a large vial containing an egg mass freshly collected 

 from the field. Within a few days after being thus confined she was 

 observed in the act of oviposition, and parthenogenetic reproduction 

 ensued. Her progeny began to issue 

 February 16, and up to February 25 

 no less than 28 males were reared. 



The experiment was tried of con- 

 fining her with several of her asexu- 

 ally-produced progeny in the hope 

 that she might thus be fertilized and 

 produce females. The experiment FlG - ^-schedius kuvanx: Egg. Greatly en- 

 did not succeed at that time, appar- 

 ently because she was not able to deposit any more eggs. She 

 remained alive until March 2, but was dead on March 6, after at 

 least eight weeks of active life. 



The eggs from which these parthenogenetically-produced males issued 

 were known beyond per ad venture of a doubt to have produced Sche- 

 dius, and never to have contained any other parasite, and together 

 with those from which Anastatus, Tyndarichus, and Pachyneuron 

 were known to have issued, made complete the series which was to 

 be dissected. 



The dissection work was mostly done by Mr. Smith, but he was 

 not alone when it came to puzzling over the problems in parasite 

 anatomy and parasitic interrelations which this work produced in 

 abundance. The contents of the individual eggshells were scruti- 

 nized with the utmost care, and slowly the various anatomical 

 remains found therein were associated with one parasite or another. 



In the course of these studies it was discovered that Schedius 

 deposits a large egg (fig. 18), which is supplied with a very long 

 stalk. The egg is placed within the body of the unhatched but 

 fully formed caterpillar, with the end of the stalk projecting outside. 



