264 DIFFERENTIATION AND SPECIFICITY' OF STARCHES. 



prossiire facets ; the larger ones have a small cavity and frequently several radial fissures. Sim- 

 l)ie spherical and spherical-oval grains are also observed; size 13;u. These apparently belong 

 to the centric-spherical type. Some of the polyhedral grains may also be simple forms. 



RoUbcella arimdinacew Hochst. (Crraminacew.) Dry endosperm. — Separatetl-grains with one curved 

 surface and 1 to 4 pressui'e facets; instead of the hilum a small cavity is usually observed 

 from which single fissures sometimes radiate. Size 3 to 8/i. Compound gi-ains are less freely 

 observed; they probably consist of not more than 8 to 10 components. Simple centric- 

 spherical grains are also present. 



RoUbcella carnpedris Nutt. {Graminacece.) Dry endosperm. — Compound grains spherical or oval, 

 consisting of 2 to 20 equal parts (few seen free). Separated-grains, size 2 to 10//; some with 

 one curved surface and 1 to 6 pressm-e facets; others completely polyhedral; the larger ones 

 usually with a small cavity and often with single radiating fissures. Also simple grains, 

 spherical or spherically-oval; size about 12ju; the larger ones with a small central cavity and 

 several radial fissvues, belonging to the centric-spherical type (type 1). Many of the poly- 

 hedral grains may also be simple. 



Lucwa colorata Hochst. {Graminacece.) Dry endosperm. — Separated-grains with 1 curved surface 

 and 1 to 5 pressure facets, hollow. Size 3 to 11/'. Compound grains of not many components 

 are very scarce; also simple hollow grains almost round, rarely oval, and somewhat com- 

 pressed. Size about 13^. The simple and the separated-grains (the former about one-half 

 to one-third as numerous as the latter) look exactly alike; the central cavity in both is large, 

 uneven, angular, jagged, or extends into short radial fissures. 



Wachendorfia liirsuia Thumb. {Hamiodoracece.) Dry endosperm. — Compound grains (most of 

 which have fallen apart) consist of 2 to 12 and more components, which are almost equal, 

 and regularly or irregularly arranged. Separated-grains, size 3 to 20/i; rounded-angular or 

 polyhedral, with large or small cavity which is frequently very conspicuous. The starch 

 gives the impression of having been affected by heat. 



Hcemodorum (a species from Swan River). {Hwmodoracem.) Dry endosperm. — Compound grains 

 almost round to oblong and pear-shaped, frequently somewhat irregular, consisting of 2 to 

 10 almost equal components (frequently arranged 4 in a square, and sometimes in a row), 

 rarely falling apart; lines of division sometimes indistinct or entirely wanting, so that the 

 cavities of the components are seen, as in type 12. Size about 28/^. Single components, 

 size about 13/i; almost oval and have rather large, often slit-hke cavity. Simple grains, 

 size about 16/i; oval, and slightly compressed with a slit-like cavity. It is rather uncertain 

 whether these belong to the eccentric or to the oval tj'pe. A constant analogy which the 

 compound gi-ains of few components holds with those of the seeds of Leguminosce is in support 

 for the latter type. 



Barbacenia rogieri Hort. {Amaryllidacece.) Dry endosperm. — Separated-grains more or less poly- 

 hedral, frequently with sharp angles and edges; isodiametric or twice as long as broad; with 

 a central almost round or elongated cavity from which radial fissures diverge. Size 3 to 

 18//, width about 14/j. Few compound grains are less seldom present; they consist of 2 to 8 

 components. 



Hohenbergia strobilacea Schult. fil. (Bromeliacece.) Dry endosperm. — Compound grains spherical or 

 oval, sometimes somewhat irregular as a result of pressure, consisting of 2 to 5 almost equal 

 components which are arranged either irregularly or regularly (3 in a triangle or 4 in a square 

 or tetrahedion). Size about 15/i. Separated-grains almost isodiametric; thej' frequently have 

 a small central cavity, without fissures. Also simple centric-spherical grains are also found. 



Billbergia zebrina Lindl. {Bromeliaceos.) Dry endosperm. — Compound grains spherical-oval, rarely 

 irregular; consisting of 2 to 6//, rarely more, almost equal components which are regularly 

 arranged. Size about 21/j. Separated-grains with rather sharp angles and margins; with 

 a small central cavity from which single fissures occasionally proceed. Size 4 to 10//. Simple 

 centric-spherical grains are also present. 



Pitcairnia albucwfolia Schrad.; Pitcairnia punicea Lindl. (Bromeliacece.) Dry endosperm. — Separ- 

 ated-grains with 1 to 4 i^ressure facets with rather sharp angles and margins; usually with a 

 large cavity from which single railial fissures occasionally proceed. Size 4 to 12 and l(3/i. 

 Compound grains few, consisting of 2 to G components. Simple centric-spherical grains are 

 also present. 



