86 PLANT PHYSIOLOGY 
starch, drops of oil are produced in the cytoplasm and 
cell sap, or cane sugar (Ci2H2011) or some other 
carbohydrates. 
126. The further fate of the carbohydrates formed in 
photosynthesis is varied. The excess of glucose or other 
sugars in the chlorophyll-bearing cells in addition to 
what is put aside temporarily in insoluble form as starch 
diffuses through the adjacent cells and finally reaches 
the vascular bundles where it enters the parenchyma cells 
bordering the sieve tubes. It probably diffuses through 
these into the latter in which it diffuses and is probably 
also carried by streams of protoplasm to those parts of 
the plant where the tissues contain less glucose. 
Here it diffuses out into these tissues. Besides passing 
in the sieve tissues diffusion doubtless occurs from cell 
to cell throughout the parenchyma of the cortex espe- 
cially in those cells bordering on the sieve tubes. Dur- 
ing the night the starch grains that have accumulated 
in the chloroplasts in day time are transformed into 
glucose which diffuses in the manner just described. 
127. The carbohydrates transported in this manner 
may be stored up as reserve food in various forms. Thus 
they may be transformed into starch in the leucoplasts of 
the storage organs, e.g. tubers of potato, roots of sweet 
potato (Ipomoea batatas), pith of various twigs such 
as apple, sassafras, etc., medullary rays of many trees, 
endosperm or cotyledons of seeds, etc. Cane sugar may 
be found in many plants such as beets, maple, sugar cane, 
etc. Inulin is found in the roots of many plants par- 
ticularly those belonging to the order Asterales. Trans- 
formed into fats they are found in many seeds, e.g. flax, 
cotton, peanut, castor bean, as well as in the bulb scales 
of onion, leaves of cabbage, etc. In the seeds of many 
palms, e.g. date, and the wood of many trees, e.g. elm and 
