34 THE UNIVERSITY OF OKLAHOMA 



shows that neither adults nor offspring can live and reproduce at a 

 temperature of 51° C. Further the result indicates that a greater 

 number of offspring was obtained when moisture was provided 

 than when it was not. 



The fourth test (Table 4) was to determine the effects of 

 acids upon the development of Bruchus. The results of this experi- 

 ment show that concentrated sulphuric acid produce no progeny, 

 while an amount of acid in the water just sufficient to turn litmus, 

 produced 325 offspring in the shortest time (14 days) ever ob- 

 served. This is probably due to an optimum humidity because 

 when ^^ H.,0 p!us %. H^SO^ was used fewer offspring (219) were 

 obtained at the end of 18 days, due probably to a lessened humidity. 

 When y2 HjO plus yi H^SO, was used no offspring were found, 

 or in any higher concentrations. With nitric (HNO^) acid no 

 offspring were found, except in very dilute solutions ; then the 

 life cycle was lengthened to 18 days. In other words sulphuric 

 acid hastened the life cycle while nitric acid lengthened it. Nitric 

 acid has a lethal affect, while sulphuric acid furnishes an optimum 

 humidity. But hydrochloric (HCl) acid acted as the greatest re- 

 tardcr to metabo'ism in the developrrent of this Insect, requiring 36 

 days for progeny to appear, when dilute solutions were used. Nc 

 offspring, however, appeared in any mere concentrated solution of 

 this acid. 



The fifth test (Table 5) was to determine the affect of alkali 

 upon the life cycle. Sodium hydroxide was the only one used and 

 offspring 'ippeared in concentrated as well as in dilute solutions. 

 .In dilute concentrations it required 36 days for offspring to 

 appear and 42 days in concentrated alkali. Alkali retards the 

 life cyc^e of Bruchus 



The sixth test (Table 5) was to try the effect of alcohol upon 

 the life cycle. The result was negative in all concentrations ; that 

 is, nc offspring. The fumes of alcohol gave a lethal effect. 



The seventh test (Table 6) was to determine the death 

 points of the different mutants. The Red (R) died at 50.5° C, 

 the Black (Rb) at 50° C, the Wild Stock at 49.5° C, the gray 

 (Rs) died at 47° C, the tan (r r) at 48° C, and the white (Rw) 

 died at 47° C. The result shows a rather close agreement for each 

 allelomorph; however, the reds would produce offspring at a higher 

 temperature than any other of the mutants. 



The eighth test (Table 7) vv^as tc determine the effect of cow 

 pea meal upon the life cycle. The result is negative but offspring 

 v/ere obtained with cracked beans however. It appears that the 

 larvae must have som.ething to bore into. 



