16 



MISSOURI AGR. EXP. STA. RESEARCH BULLETIN NO. 21 



The results obtained are summarized in Table 3. The dates in the 

 table show when the twigs were collected. Calculations were based 

 on the fresh weight which was practically the same as the weight 

 after the preliminary treatment. The KOH bulbs were weighed 

 once every twenty-four hours. 



TABLE 3 CO 8 PRODUCED BY ETHERIZED AND UNTREATED TWIGS OF 

 DIFFERENT SPECIES, AT 15-18 C. 



Discussion of Results. From the data it is seen that the normal 

 respiration of different species varies greatly, being most vigorous 

 in the mulberry, next highest in the oak and least in case of the ash 

 and apple. In all cases etherization caused an increased production 

 of CC>2. The relative amount of increase, however, varied with the 

 different species, as may be seen by comparing the ratios given in 

 Table 4. These ratios were obtained in the manner previously 

 explained. 



TABLE 4 RATIO OF CO 2 PRODUCED BY ETHERIZED, TO CO 2 PRODUCED 

 BY UNTREATED TWIGS 



The figures show that the stimulating effect of ether was most 

 marked in case of the apple, the etherized material having produced 

 more than three times as much CO 2 as the untreated. The ratio 

 greatly increased from the first until the third day. In mulberry, 

 etherization did not cause such a great increase in CO 2 production 

 as in the apple, but it was greater than with ash or oak. The increase 



