5i6 



ascribed to a strong exhalation of carbon dioxid. I have not been able to 

 prove experimentally an increase of sugar in the tubers, by a two days' 

 retention in a carbon dioxid atmosphere. \e\ erthelcss, it might be possible 

 that some effect would be noticeable after a longer time. The statement 

 gains probability from a work by Bachet' and Savelle, according to which, 

 by the use of carbon dioxid with a somewhat higher temperature and greater 

 pressure, starch flour was rapidly turned into dextrine and grape sugar, espe- 

 cially if the process of saccharification was facilitated l)y the addition of 

 gluten. It can be assumed that, because of an abundant supply of carbon 

 dioxid in the above mentioned case from Reiner/., natural respiration is 

 repressed just as by a lower tem[)erature and the process of sugar formation 

 which, according to Miillcr. can be proved uj) to a temperature of lo 

 degrees has caused its slow accumulation. The production of saccharose 

 during germination after an increase of temperature is proved by Mar- 

 cacci's- exi)eriments with slices of potato which had been dried in the sun 

 and in an oven. In the sprouting tubers, saccharose is found in the young 

 shoots and later in the leaves (probably due to the hydration of starch). 



It is e\ident from the above that the methods of using these potatoes, 

 wliich in outward appearance are rarely distinguishable from healthy, non- 

 sweet tubers, can in no way be api)licable for frozen ones, i. e., those turned 

 U) ice. A tuber which has been frozen hard is dead and, in thawing, at 

 once falls \ictini to a high degree of decomposition. It becomes soft and 

 gi\es off water, while the cut surface turns brown at once, if not immedi- 

 ately coated with acid. 'J'hc skin separates (|uickl\- from the tk'sli. like a 

 bladder, with a development of gas. The bark cells beneath the cork layer 

 break apart because of the dissolution of the intercellular substance. The 

 cytoplasm is brown and granular and drawn back from the cell wall; the 

 protein crystalls are dark brown; the cell sap is strongly acid. 



The Ruxmxc; to Si-:i:d of 1]i:i:ts. 



!]}■ this name are characterized those specimens of sugar beets and fod- 

 der beets which set seed even in the first summer. In some years the phenom- 

 enon occurs very frequently and disturbs the harvesting and use of the beet 

 since the root is woodier than in the two-year-old beets. Opinions differ 

 as to the cause of the phenomenon. Tliev take two different i)oints of \iew ; 

 some make the constitution of the seed responsible for this, others, the 

 atmospheric conditions and especially spring frosts. In consideration of 

 the fact that actually in years when late frosts have attacked the young beet 

 plants, unusually many may be found which have run to seed and, sup- 

 ported by Aderhold's experiments with kohlrabi, to be mentioned later, we 

 will give here the present cultural retrogression. 



From the abundant literature on sugar beets we will cite only one work, 

 since it reports recent scientific investigations and makes brief references 



1 After Compt. lond 1S78; cit. in Biedermanns Centralbl. 1879, p. 544. 

 - Marcacci, A., Sui prodotti delta transformazione dell' amido, cit. But. Jalireslj. 

 isyi, I, p. 47. 



