Smith—The Organization of the Colony. 
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THE ORGANIZATION OF THE COLONY IN CERTAIN 
FOUR-CELLED ALGAE 
Gilbert Morgan Smith 
INTRODUCTORY. 
The arrangement of the cells in a few-celled coenobic colony 
presents several interesting problems. There are various pos¬ 
sible combinations of the cells of a colony composed of four cells 
arranged in a definite symmetrical structure. If the individ¬ 
ual cells are spherical (isoaxial), their arrangement may be 
either in a linear series, a plane or a pyramid. Colonies of 
isoaxial cells with the cells regularly occurring in a linear series 
QCCO 
Eigure 1. Diagrammatic representation of possible combinations of isodiametric 
cells in a four celled coenobe. Shaded diagrams represent those arrange¬ 
ments which are known to exist in nature. 
.are unknown. Tdtracoccus boiryoides West is a type of colony 
whose cells are in a plane; C oelastrum microporum N a eg. 
constitutes the only known form with axially undifferentiated 
■cells arranged in the form of a pyramid. 
If the individual cells have each a long and a short axis (i. e. 
are heteraxial ), many more colony forms are possible. The 
range of possible symmetrical arrangements is shown in Text 
"Figures 2 6. All normal coenobic colonies are symmetrical. 
