454 GENERAL SYSTEMATIC BACTERIOLOGY 



described definitely as a plant. Enlows (1920, p. 80) has summarized 

 the characteristics of the species as follows : 



Frustules 16; color light brown; transparent matrix very perceptible between 

 the frustules, less so around the edges; size "0.800 to 0.1000 of an inch." "The 

 individual organisms were transparent and slightly yellow or brown. When 

 carefully examined under favorable circumstances the cell walls appeared rigid, 

 and could be perceived passing from one flat surface to the other as dissepiments. 

 These dissepiments, as well as the transparent spaces, were from compression of 

 contiguity rectilinear, and all the angles right angles; but the bounding cells 

 bulged somewhat irregularly on the edges of the organism by reason of the free- 

 dom of pressure. These circumstances gave the whole organism the appearance 

 of a wool pack, or of a soft bundle bound with cord, crossing it four times at right 

 angles, and at equal distances." Found in the human stomach. 



Robin (1847, p. 47) characterized the genus as follows: 



Plante coriace, trausparente, consistant en masses cubiques ou allong^es, 

 composees de 16 a 64 cellules cubiques, partagees en 4 frustules, arrangees I'une 

 k cote de I'autre. Esp6ce S. ventriculi (Goodsir). Frustules 16, de couleur brune 

 claire. Masse transparente, laissant voir son interieur entre les frustules. Les 

 bords de celles sont emousses. Diametre 1/120 a 1/100 de ligne. Habite I'esto- 

 mac humain. 



The first definite inclusion of the genus in a scheme of classification 

 was the assignment of this form to a position in the tribe Glaeogenae 

 by Cohn (1875). The genus was also discussed by Luerssen (1879, p. 

 21) who mentions the species S. ventriculi Goodsir. He states that the 

 spherical cells divide in three directions of space and form cubical 

 famihes. Magnin (1880, p. 96) states that "Sarcina is very nearly 

 allied to Merismopedia, from which it only differs by the absence of 

 chlorophyll; its siliceous skeleton allies it with the diatoms." He 

 mentions no species. 



Trevisan (1879, p. 145) accepted the genus among the bacteria 

 under the subtribe Sarcineae, with the following definition: 



Cellulae globosae, divisionis tempore ovoideae, quaternatim in colonias tabu- 

 latas consociatae, tegumentis propris gelatinosis crassiusculis confluentibus 

 obvolutae. Coloniae tegumento communi destitutae. 



Two species are listed, the Sarcina ventriculi Goodsir and Sarcina 

 urinae Welcher. 



Before 1885 the genus is discussed by at least three other writers, 

 Van Tieghem (1884, p. 1114), Grove (1884, p. 20) and Winter (1880, 

 p. 48). Grove gives the definition of Winter, stating: 



