90 



The Ohio Journal of Science [Vol. XXI, No. 3, 



The earliest work on the study of translocation of starch 

 is that of Mer.i This investigator made a thorough study 

 of the changes of starch content throughout the growing and 

 dormant periods of the year in different parts of the tissues, 

 both in ordinary and girdled stems of various plants, such as 

 beech, oak, pine, etc. Similar investigations were made by 

 Rosenberg. 2 The most recent work is that of Butler, et al,^ who 

 made a thorough analytical study of the carbohydrate, nitrogen, 

 fats, phosphorus, and potassium of different parts of bearing 



/ IS\ I iS ( 1^ I IS I IS I IS I IS I IS I ) S" I IS I IS I IS 



/*fAy- Jt«*ie, . lu/y. Aua, Se.^ Och t^ov- Dec Ja.n ■ Fe-C-. /^cty. A/^r-. 



Season oj- tkt- yecir 



Fig. 1. Curves showing changes in carbohydrates in fruit spurs of apple from 

 May to April, 1919-1920. The ordinates represent the percentage of carbohydrates 

 and the abscissae, the season of the year. 



app'e trees. The writer's work is similar to that of the latter 

 investigators, so far as the carbohydrate materials are con- 

 cerned. There is, however, some disagreement in the data 

 obtained in the two cases. This is, perhaps, due to the differ- 

 ence in age and in location of the trees in different climatic 

 conditions. The data presented in this report show a seasonal 

 periodicity in the changes of the carbohydrate materials, i. e., 

 starch to sugar and vice versa, and a partial explanation of the 

 factors that bring about these changes. The data also show 

 that changes in temperature play a very important part in the 

 changes of carbohydrates in plant tissues. The fluctuations 



