IO8 HUGH GLASGOW. 



found that the development of the eggs of the squash bug was 

 in no way hindered by a very thorough treatment with a solution 

 of mercuric chloride. When such eggs were placed in bouillon 

 as a check on the thoroughness of the disinfection, they would 

 remain apparently sterile for a period of three days or more and 

 then, at about the time the experiment should have been con- 

 sidered a success, an abundant growth would suddenly appear 

 which apparently consisted of a number of different contaminat 

 ing organisms. This test was repeated a number of times, with 

 certain variations in the method of disinfection. It was thought 

 at first that perhaps the film of air surrounding the egg prevented 

 the aqueous bichloride solution from doing effective work, and 

 the eggs were accordingly first moistened with alcohol to remove 

 the film of air; but no matter how thorough the disinfection 

 was made, the confusing growth almost always appeared. 



Since there could be no question but that the surface of the 

 eggs had been completely sterilized, there remained nothing but 

 to conclude that the contaminating organism or organisms were 

 within the egg itself. 



As is well known, the eggs of birds may sometimes contain 

 bacteria while still in the oviduct, and before the shell has been 

 laid down, so that when the shell is formed they are included 

 within it. There is no reason why the egg of an insect should not 

 become contaminated in much the same way, and it was thought 

 at first that this must be the case with the eggs of the squash 

 bug. This species was accordingly abandoned, since it was 

 clearly out of the question to rear sterile individuals of it. A 

 little later in the season a few eggs were secured from specimens 

 of Mwgantia histrionica that had been received from Dr. W. E. 

 Hinds, of Auburn, Alabama; and it was decided, as a last resort, 

 to test these to see if they were also contaminated. These eggs 

 were given exactly the same treatment as had been given those 

 of the squash bug; but instead of developing the contamination 

 that appeared so constantly in the squash bug eggs, they in- 

 variably remained sterile and showed no growth whatever, even 

 when crushed immediately upon being placed in the bouillon. 



Before undertaking the rearing work on Murgantia that was 

 logically opened up by these negative results, it was decided to 



