604 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



of wheat 28-35 /a. Better cliaracters are obtained from tlie grains 

 tliemselves. 



The denseness of the pitting in the transverse cells of wheat gives 

 them a chaplet-like appearance. The shell or pericarp is often 

 difficult to meet with in the finer kinds of meal. 



Skin, average thickness 



Epidermal cells of the skin or pericarp — length 



}5 )> V breadth 



„ „ porous pitting 



Sub-epidermal transverse-cells — length . . 



„ ,, breadth.. 



„ „ thickness of walls 



„ „ pitting 



Starch-cells— average larger diameter .. 



„ shorter diameter . . 



Iso-diametrical starch-cells — diameter . . 



Eye. 



Good characters are also obtained from the hairs. Before grind- 

 ing, both ends are removed from the grain ; the embryo-end on account 

 of the oil which it contains ; the opposite apex on account of its hairs ; 

 but a few hairs are still to be found in the meal, which give the 

 foUowinet characteristics : — 



Length of hairs 



Diameter of the largest . . 



„ at the bulbous base . 



„ of the smallest .. 



„ at the bulbous base . 

 Thickness of wall of the hair . 

 Breadth of cell -cavity 



Rye. 



Wheat has therefore thick-walled hairs with narrow cell-cavity ; 

 rye thin-walled hairs with wide cell-cavity. 



V. Berthold * confirms in the main Wittmack's statement. He 

 finds the gum-cells of wheat to.be decidedly larger than those of rye; 

 the former measuring 3, the latter 1 • 5-2 /x. The thickness of the 

 wall of the hairs of wheat he states at 5-8, of rye 3-6 /x ; the diameter 

 of the cavity of the former 1 • 5-4, of the latter 4-12 /x. 



Hunting for Lost Glaciers with a Microscope.t — Considerable 

 work has been done in this direction in Germany and elsewhere by 

 various observers, work with which geologists are more or less 



* Zeitschr. f. Landwirthsch. Gew., &c., 1883, pp. 1-3. See Bot. Oentralbl., 

 xiv. (1883) p. 247. 



t Nova Acta Acad. Leop.-Carol., xlv. p. 35. See Science, i, (1883) p. 177. 



