180 THE BURSTING-POINT OF SOME STARCH- CELLS. 



the amyline together and preventing dissolution ; see Figs. XXL 

 and XXII. At 194° the cells had not collapsed, ebuUition for 

 several minutes being required to completely distend and empty 

 them. 



Wheat-Starch. — At 134S a nucleus and concentric rings were 

 apparent, and the corpuscles were swelling. At 140? a nucleolus 

 was very distinctly seen. At 150^ a few cells were burst; see 

 Figs. XXIII, XXIV., XXV., XXVI. At 158^^ some large 

 cells began to lose shape. For appearance at 164° see 

 Figs. XXVII. and XXVIII. ; and at 174^ Fig. XXIX. At 176^ 

 see Fig. XXX., and at 177^, Fig. XXXI. At 180^ the form of 

 the cells was beginning to disappear. After remaining at 180^ a 

 few minutes, all the cells appeared to have lost their original form, 

 and their contents were dissolved out. 



The chief characteristic of Wheat-Starch was the gradual 

 swelling of the cells without distinct openings appearing, as in 

 other Starch-cells; only one exception to this was seen at 164°. 



Potato-Starch. — At 140? the cells began to split open ; see 

 Figs. XXXII. and XXXIII., the fracture commencing at the 

 hilum. At 153^ the centre of the cell was gradually opening out, 

 Fig. XXXIV. At i58<=* all the large cells were burst. At 170^ 

 all the large cells were fully open. At 180^ all the large cells 

 were gone, and at 184^ all the cells were gone. 



Potato-Starch, after being exposed to a vioist atvwsphere for some 

 flays. — Very few of the cells shewed concentric rings, but a curious 

 fracture at the hilum had occurred, from which other fractures 

 extended. These fractures were of a very interesting character, 

 being circular and saucer shaped, but with the centre raised ; see 

 Fig. XXXV. 



As the cells rolled in the liquid, it was distinctly seen that this 

 fracture was circular (see Fig. XXXVI.), having a central point 

 with radiating markings, and that it was in all cases in the longitu- 

 dinal axis of the cell, a little above the centre, coinciding 

 with the hilum. 



From the foregoing results it is evident that a temperature of 

 180*^ F. is sufficient to entirely dissolve the various starches 

 experimented with, but, unfortunately, nothing of value to the 

 analyst has been obtained, although the work may be of sufficient 

 interest to place the results upon record. 



