36 



SCIENCE-GOSSIP. 



[Feb. 1, 1866. 



starch yielded by this millet is small, of a polyhedral 

 form, and very similar in all respects to that last 

 named, except in being rather more minute. 



Peas {Pisum sativum). — The starches of peas, 

 beans, and lentils offer a type differing from all the 

 preceding in the sinuosities of the margins of the 

 granules. That of the pea has alternate elevations 

 and [depressions on the surface, and a deep central 

 groove, from which the furrows diverge. 



Fig. 33. Peas. Fig. 34. Beans. 



Beans (Phaseohs vulgaris). — These granules are 

 also remarkable for the undulations of their surface. 

 They are larger than those of the pea, and present 

 the'same appearance of an elongated hilum, which 

 is in reality the central groove. 



Sago {Sagtu RumpMi).—TiiG granules of Sago 

 starch are irregularly elliptical, from '0005 to "0022 

 of an inch long by "0008 to "0010 of an inch wide. 

 They are generally more or less broken, with a cir- 

 cular hilum near one extremity. A few faint con- 

 centric rings are discernible on some of the granules. 



Fig. 35. Sago. Fig. 36. Cycas. 



Cycas (Cycas circinalis). — These granules are of a 

 remarkable structure, apparently formed by the ag- 

 glomeration of sphserical grains, which on separation 

 exhibit a sharp angular form at the points of contact. 

 Each of these portions has its individual hilum. 



Potato (Solatium tuberosum).— -These granules 

 are intermediate in size between those of the West 

 Indian arrowroot and Tous les Mois. The most 

 characteristic resemble an oyster-shell, all exhibit a 

 hilum, and the concentric lines are larger and coarser 

 than in most starches. 



Sweet Potato (Batatas edulis). — The starch of 

 the Sweet Potato bears considerable resemblance to 

 that of the Cycads, in the angular form of some of 

 the faces of the granules and the rotundity of 

 others. It is, however, smaller and less distinctly 

 marked. 



Tous les Mois (Canna edulis, $•<?.). — This is the 

 largest and most beautiful of all the starches. The 

 characteristic granules are egg-shaped, with a ring 

 or hilum near one end, surrounded by rings or plaits 

 which are fine, crowded, and regular. Under the 

 polariscope the crosses are clear and better defined 

 than on any other starch. 



Fig. 39. Tous les Mois. 



Fig. 40. Tapioca. 



Tapioca (Jatropha manihot). — In this starch the 

 granules are muller-shaped, though, when seen end- 

 ways, they appear circular. The hilum is sometimes 

 circular, and at others a slit with a few faint rings. 



Bermuda Arrowroot (Maranta drundinacea). — 

 The granules are much smaller than those of Tous 

 les Mois, narrow, and tapering, frequently termi- 

 nating in an obtuse point, while some display small 

 papillae or knobs. The hilum is generally a ring, 

 but occasionally a slit, in the narrow end, and 

 around it a few faint rings may be observed. 



Fig. 41. Arrowroot. 



Fig. 42. Hyacinth. 



Fig. 37. Potato. 



Fig. 3S. Sweet Potato. 



Indian Arrowroot (Curcuma august/folia). — 

 The granules in this starch are long, narrow, and 

 shell-shaped, the hilum is a ring in the narrow ex- 

 tremity of the granule, but it is very indistinct. 

 On all the granules lines or plications occur, which, 

 however, mark only segments of a circle. 



Hyacinth (Agraphis nutans). — The granules of 

 the bulbs of the hyacinth somewhat resemble those 

 of the lily, but are smaller, more irregular, and like 

 them often exhibit more than one hilum. The gra- 

 nules are also often constricted in the centre. 



Lily (Lilium candid urn). — These granules are 



