18 SUGAR BEET SEED. 



the seed, by allowing moisture, etc., from the environ-, 

 ment in which the seed may be, to enter by osmosis in 

 the proper proportions. 



Drs. Westler and Stoklasa have made a very thor- 

 ough microscopical and chemical examination of the 

 testa, and have discovered that the tissue is largely 

 made up of crystals of oxalate of lime, from which it is 

 concluded that nearly all the calcium of the seed is 

 found in the outer and inner layers of the testa. (The 

 inner cellular layer of the exterior of the testa consists 

 of small cells almost round. The inner yellow ochre 

 layer, on the other hand, consists of a single layer of 

 polygonal elements, which are smaller and not so flat 

 as those of the outer portion of the testa.) It has been 

 possible to extract several grains of the lime oxalate 

 from the testa, and this substance has served for the 

 estimation of pentosanes, by the Tollen-Kruger 

 method. From the quantity of phlaroglucide, tliat of 

 the furfurol may be calculated. On a basis of dry sub- 

 stance, it was found that there is 10.24 pcr cent, furfurol 

 for 18.85 per cent, pentosane. These figures show that 

 the testa is very rich in pentosane ; it is said that these 

 substances form a chemical combination with the cellu- 

 lose of the testa.* 



While the exterior coating is dark brown and con- 

 sists of two layers of cells which are very flat, some 

 authorities declare that seed which will not germinate 

 is yellow green; on the other hand, seeds that have 

 great germinating powers have the tip end of their 

 root of a color which approaches violet. The seed,' 

 M, N, (Fig. 16) taken as a whole, is blue white. If we 



♦These ligno-i^elluloses, aecorciiiig to Gross and Bewan, li»ve the 

 following formula: 



4C6 Hio O5 Cg Hio O5 do HigOg 



cellulose Pentosane Keto-liexan gro\ips 



Noii-oelluloses, 



