The principles of biology . common support, and establish among them a more decidedcommunity of nutrition. Among the Ascidians, another order of the Molluscoida, thisgeneral law of morphological composition is once more dis-played. Each of these creatures subsists on the nutritiveparticles contained in the water which it draws in throughone orifice and sends out through another ; and it may thussubsist either alone, or in connexion with others that arein some cases loosely aggregated and in other cases closelyaggregated. Fig. 156, Fhallusia mentula, is one of the soli-. tary forms. A type in w
The principles of biology . common support, and establish among them a more decidedcommunity of nutrition. Among the Ascidians, another order of the Molluscoida, thisgeneral law of morphological composition is once more dis-played. Each of these creatures subsists on the nutritiveparticles contained in the water which it draws in throughone orifice and sends out through another ; and it may thussubsist either alone, or in connexion with others that arein some cases loosely aggregated and in other cases closelyaggregated. Fig. 156, Fhallusia mentula, is one of the soli-. tary forms. A type in which the individuals are imited by astolon that gives origin to them by successive buds, is shownin Perophora, Fig. 157. Among the Botryllidce, of which one THE MORPHOLOGICAL COMPOSITION OF ANIMALS. 87 kind Is drawn on a small scale in Fig. 159, and a portion oftlie same on a larger scale in Fig. 158, there is a combinationof the indiyiduals into annular clusters, which are themselvesimbedded in a common gelatinous matrix. And in thisgroup there are integrations even a stage higher, in whichseveral such clusters of clusters grow from a single the compounding and re-compounding, appears tobe carried further than anywhere else in the animalkingdom. Thus far, however, among these aggregates of the thirdorder, we see what we before saw among the simpler aggre-gates of the second order—we see that the component indi-vidualities are but to a very small extent subordinated to theindividuality made up of them. In nearly all the forms in-dicated, the mutual d
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectbiology, bookyear1864
