232 DIFFERENTIATION AND SPECIFICITY OF STARCHES. 



Colocasia odora Brongn. (Aroidew.) Dry seed. — Grains rounded to oval-conical, mostly somewhat 

 irregular; half to just as broad as long; the narrower forms not compressed; the broader ones 

 compressed to about half their width; no lamellte; instead of the hilum there appears fre- 

 quently a small round cavity from which a single fissure may emerge, more often a slit-like 

 cavity, which from the broad aspect appears delicate and from the narrow aspect more 

 clearly defined; hilum end in the small forms is broader than the distal end; eccentricity 

 about one-third and one-fourth. Length about 22 to 26^, width about 20/i. The structure 

 is not very clearly defined, frequently approaching the conical type (type 7) and the 

 cuneiform or compressed type (type 8). Doublets and triplets are also found. 



Mammea americana Linn. {Guttiferw.) Dry cotyledons. — Grains mostly oval or elongated-oval, 

 rarely almost rounded or conical; usually twice as long as broad; circular in transverse sec- 

 tion; the broadest and at the same time somewhat irregular forms are seldom slightly com- 

 pressed; no lamellae; instead of the hilum a small cavity is usually observed, generally with a 

 cross-fissure and several radial fissures ; ordinarily the grains are of almost equal width through- 

 out their entire length ; now and then narrowed at either the proximal or distal end, or even at 

 both ends; eccentricity mostly one-third to one-fourth (seldom one-fifth and one-sixth). 

 Length about 55^, thickness about 35/li. Rich in starch; poor in oil. 



Type 10. Grains Simple, Structure Obscure. 



Nageli places here all the species of starch, the structure of which, mostly on account of their 

 diminutive size, is either not fully developed or not identified, and hence remains doubtful as to 

 which of the foregoing types they belong. The grains, as a rule, are imdoubtedly simple. Now 

 and then some separated-grains which are no longer recognized as such may occur. Lamellae, hilum, 

 cavities, fissures, and clefts are seldom mentioned, because they have not often been demonstrable. 



Vaucheria tuberosa A. Braun. (Algce.) Dry tuberous swollen ends of root-like organs. — Grains (all simple) 

 oval to elongated, lanceolate, mostly somewhat unequal laterally, or elliptical and constricted 

 in the middle, reniform, frequently somewhat irregular; L5 to 3.5 times as long as broad; the 

 broadest ones compressed to about half the width ; sometimes from the narrow aspect a deli- 

 cate longitudinal slit is observed. Length about IB/z, width about 7ai, thickness 2.5 to 3.5;u. 



Equisctum hyemale Linn. (Equisetacece.) Young <w6ers.— According to Leon Soubeiran (Journ. 

 Pharm., 1854, xxv, 182) the smallest grains are spherical, the larger ones elongated, and the 

 largest ones pear-shaped; there are many very irregular forms with dentate projections on the 

 circumference; lamellae and hilum rare and indistinct. Length 50 to 60yu, width 10 to 30^. 



Olfersia undulata Presl. {Filicinece.) Dry root-stock.- — Grains rounded or rounded-triangular, occa- 

 sionally oval, not at all or very slightly compressed, many with a small or a large cavity. 

 Size about IQfx. 



Polypodium vulgare Linn. ; Radix polypodii. (Proteacece.) Dry root-stocks.— Grains rounded; rounded- 

 triangular, oval, frequently somewhat irregular; compressed to about half or more of their 

 width; many are thickened at the more convex margin or at one angle of the triangle, and 

 at the opposite broad margin thinned and squared; without lamellae, hilum, or cavity (even 

 after roasting and boiling, the hilum is not visible). Size about 9 to 11/^. Many of the grains 

 agree closely in their form with those of the cuneiform tj-pe (type 8). 



Polypodium distans Kaulf. {Proteacece.) Dry root-stock. — Grains rounded or rounded-triangular, 

 rarely oval; compressed to about one-third of their width; elongated from the narrow aspect. 

 Size about 14^. 



Adiantum capillus-veneris Linn. {Filicineoe.) Dry root-stocks. — Grains rounded to oblong, mostly 

 oval, sometimes somewhat irregular; narrow ones little or scarcely compressed, the broader 

 ones to about half their width; from the broad aspect indistinct fissures are occasionally 

 observed; from the small aspect the grains are elongated-oval, and generally have a distinct 

 longitudinal slit. Length about 30;u, width about 20ai. In spite of the size of these grains, 

 it is doubtful to which type they belong. In form and median cleft they resemble the centric- 

 oval and centric-lanceolate types. 



Asplenium marinum Linn. {FilicinecE.) Dry root-stock. — Grains rounded or oval, often somewhat 

 irregular; the broad ones compressed to about half their width; the majority have a large 

 cavity. Size about II/jl. Isolated doublets are also present. 



