948 FOODS AND FOOD ADULTERANTS. 
of cells, known as “ Mitscherlich bodies.” They are now considered to 
be epidermal hairs, but it is not decided as to whether they belong to. 
the membrane just described or to the surface of the cotyledon. Neither 
the settlement of this question nor the membrane and hairs, are of any 
great importance for our purpose, since both of these structures are 
very rarely met in recognizable form in the commercial preparations. 
After the removal of the husk and the membrane just described, the 
two fleshy, much-folded cotyledons, or seed leaves, remain, inclosing 
the radicle (the embryo stem of the undeveloped plant) at the larger 
end of the bean in a manner not a little suggestive of the retracted 
head of aturtle. Examination of a thin section shows the cotyledon to 
be made up of comparatively thin-walled, closely packed, polygonal 
cells (see Plate xLvit). The most of these cells are filled with starch 
grains, fat, and albuminous material; isolated or small groups of cells 
are homogeneously filled with the reddish brown to violet pigment, 
cocoa red. Fiber bundles with spiral cells, similar to those of the husk, 
occur in the veins. 
The starch grains are spherical, or nearly so, have a very indistinct 
nucleus, react only feebly with polarized light, rapidly lose the blue 
coloration imparted by iodine, and show only a slight tendency to 
unite in the form of compound grains; three or four is usually the 
maximum number so united. The size of the grains of cocoa starch is 
usually stated to be 0,003-0.010 mm. The following measurements 
were made in this laboratory: 
Measurements of starch grains from a sample of unprepared cocoa beans. 
Millimeters. 
IAT AMIS MME ASULCC lek: ier le vy ae eee ees rele etna eee ey 0. 003 
fel oraIns MeASUTe Gey ey A eve EN DCR Eee eee 0. 004 
l4craims measumed) fs oie ii 2 a As se Goi. tele 2 vee ed 0. 005 
Gisrains Measure Che oes ae io ee eet ne eee rek reece eee 0. 006 
HP OTAIMS MMEASULEO Se ese ace ee atest cler te en ars Cee eee ere res 0. 007 
2 iO TANES TNS AS UEC C eeepee ee yee sere armies aye toe eters Nese eevee 0. 008 
I eraimMeMeaASUMe Me ree eee ele see ren eran een ene rey ieee 0. 009 
oral Cas uredess ers Po ee rise 2 eee Cece in reenact 0. 010 
51 Average Ofeo Sarr ania ies ener eee cera ey ernest eee 0. 0054 
Measurements of starch grains from Walter Baker § Co’s. “‘ cracked cocoa.” 
Millimeters. 
SI OTAMNS MOASULCG 2 2 oy le iahic ot | pee ee cry lee ge ee ieee 0. 002 
Viorains measured 3225. 25:6 2 ls ee nee ee re eee 0. 003 
12 prains measured “ss se. S22 olen fee Nee ee eee 0. 004 
Ae rains MeCASUTOC YN: see Berea oe eee ae oeee Dae homer ames See ae 0. 005 
TS Sraims measured a8 oi evel 2 2a DAP eS EU pee ye Nee Re es Rea -- 0.006 
28 CTAINS MEASUTOG no op.) 5 ois Cee Bl. a kaa ues pu eee Meets 0. 007 
Terains measured. io 0. so eee eee eee ee oe ee ee 0. 008 
3 CTAWMS MMEASUT OM 1p Sie See es eats ae a bet ate er me Tae 0. 009 
SPraims measured) soos sec ee See Cee eee oe tee eens peeve 0. 010 
2 prainsimeasuredis 225s She Ae Se ee eee tects oe eerie 0. 012 
100 Average of 100 grains 65.2 ashes eee ie een ROU 
