EXAMIIfATIOX OF THE BEET. 77 



merons experiments to ascertain what this relation was ; 

 the most important of these were by Walkhoif, Scharcht, 

 Bretschneider,^ Champignon, and Pellet,^ etc., and 

 from these there can be no doubt as to the truth of the 

 above hypothesis. If a beet be examined when it is 

 a Uttle larger than the above, we can see that the 

 various new zones'^ have continued forming in exactly 

 the same manner, and the utricles have remained per- 

 fectly transparent. (See fig. 10.) Mr. Decaisne tells us 

 that in the greater number of roots the vascular group 

 is central and unique, and becomes larger with age, 

 and is surrounded by a layer of various thickness of 

 cortical parenchyma composed of utricles. 



' Mr. Walkhoff gives in his book experiments of Bretschneider, these being 



to ascertain the proportions existing between the number of zones and leaves. 



_ J 1 J Concentric zones 



Leaves developed. ^^ ^^^ ^^^t_ 



The 20th July ... 9 to 10 4 



9th August . . 15 " 18 5 to 7 



31st August . . 18 " 28 7 " 8 "j Many of these 



15th September - . 18 " 28 7 "8 I leaves were yel- 



30th September . - 18 " 28 7 " 9 | low and were 



16th October . . 18 " 28 8 " 9 J partly gone. 



* The experiments of Champignon and Pellet are even more interesting. 

 These gentlemen suppose that each zone is subdivided in two. 



Per cent, of sugar. No. of leaves. No. of zones. 



f 15.7 42 48 



Vilmorin's seed, \ 14.8 39 36 



[ 13.8 31 32 



f 12.2 23 28 



Ordinary seed, ] 



( 11. 19 20 



* Some authors contend that the number of zones in matured beets is limited 

 to 7 ; to those going to seed the following year 10; but we cannot indorse this 

 statement, as it seems to vary greatly, and consequently no rule can be given. 



