40 



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



V, Fig. 5). On the sixth day, i. e., during that period when untreated 

 twigs were producing more CC>2 than treated, some lots were again 

 removed from the respiration chambers and placed under condi- 

 tions favorable for growth. After growing four days, these twigs 

 were immersed in formalin as in the first case. The following obser- 

 vations were made: "The etherized twigs which were supplied with 

 warmth and moisture and other conditions necessary for growth 

 within a few days after treatment have made more growth during 

 four days than similar etherized twigs which were not placed under 

 favorable growing conditions until six days after being treated. 

 The untreated twigs in the first case have made slightly less growth 

 than those in the latter case." In other words, the respiratory activ- 

 ity of the tissue which may be determined while the twigs are appar- 

 ently dormant, serves as an index to the relative amount of growth 

 which would occur if the tissue had favorable conditions for growth. 



5. Fungi on Treated Twigs. Whenever the cut surfaces of 

 etherized twigs were left exposed in a damp basement room, Asper- 

 gillus and Penicillium grew abundantly on them. Under the same 

 conditions the untreated twigs showed no infection by the molds 

 except in a few cases during the close of the dormant season. 



6. Color Changes in Water Extract of Twigs. Decided color 

 changes were observed in the water extract of the twig material. 

 The following case is typical. 



King David apple twigs were collected March 18, 1914. Some 

 were etherized and some remained untreated. Cold water extracts 

 were then made of both lots using 100 cc. water to leach 10 gr. of 

 twig material. A number of test tubes received 10 cc. each of the 

 extract from treated twigs; others received 10 cc. of extract from 

 untreated material. The subsequent treatments which were given, 

 as well as the observations made, are recorded in Table 13. 



TABLE 13 COLOR CHANGES OCCURRING IN WATER EXTRACT OF ETHERIZED 

 AND UNTREATED KING DAVID APPLE TWIGS 



