The principles of biology . individuals last dealtwith, we have to note both the shapes of the individuals thusunited, and the shapes of the aggregates made up of them. Such of the fixed Mydrozoa and Actinozoa as form branchedsocieties, continue radial; both because their varied attitudesdo not expose them to appreciable differences in their rela-tions to those surroundiag actions which chiefly concernthem (the actions of prey), and because such differences, evenif they were appreciable, would be so averaged in theireffects on the dissimilarly-placed members of each group asto be neutralized i
The principles of biology . individuals last dealtwith, we have to note both the shapes of the individuals thusunited, and the shapes of the aggregates made up of them. Such of the fixed Mydrozoa and Actinozoa as form branchedsocieties, continue radial; both because their varied attitudesdo not expose them to appreciable differences in their rela-tions to those surroundiag actions which chiefly concernthem (the actions of prey), and because such differences, evenif they were appreciable, would be so averaged in theireffects on the dissimilarly-placed members of each group asto be neutralized in the race. Among thetree-like coral-polypedoms, as well as insuch ramified assemblages of simpler poly-pes as are shown in Figs. 149, 150, wehave, indeed, cases in many respects paral-lel to the cases of scattered flowers (§ 233),which though placed laterally remain radialbecause no differentiating agency can actuniformly on all of them. Meanwhile, in the groups which these united individuals compose, we see the shapes of. THE GENERAL SHAPES OF ANIMALS. 175 plants further sinndated under a farther parallelism of con-ditions. The attached ends differ from the free ends as theydo in plants; and the regular or irregular branches obvious-ly stand to environing actions in relations analogous to thosein which the branches of plants stand. The members of those compound Coelenterata which movethrough the water by their own actions, in attitudes that areapproximately constant, show us a more or less distinct two-sidedness. Diphyes, Fig. 259, furnishes an example. Each
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectbiology, bookyear1864
