ANATOMICAL SYSTEMS.

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the same sum of systems of organs as Man,” and the wholeof his system is intended to impress emphatically thisview. The separation of Man from the animals, notmerely as a class but as a still higher division, is especiallymaintained upon that ground.

The principle of classification adopted by Ehrenbergis purely anatomical; the idea of type is entirely setaside, as is shown by the respective position of hisclasses. The Myeloneura, it is true, correspond to thebranch of Vertebrata , and the Sphygmozoa to the Articu-lata and Mollusca ; but they are not brought together onthe ground of the typical , plan of their structure, butbecause the first have a spinal marrow, and the other aheart or pulsating vessels with or without articulationsof the body. In the division of Tubulata it is still moreevident how the plan of their structure is disregarded, asthat section embraces Radiata, (the Echinoidea and theDimorphsea,) Mollusca , (the Bryozoa, ) and Articulata, (theTurbellaria , the Nematoidea, and the Rotatoria, ^ whichare thus combined simply on the ground that they havevessels which do not pulsate, and that their intestine is asimple sac or tube. The Racemifera contain also animalsconstructed upon different plans, united on account of thepeculiar structure of the intestine, which is either forkedor radiating, dendritic or racemose.

The limitation of many of the classes proposed byEhrenberg is quite objectionable, when tested by theprinciples discussed above. A large proportion of themare, indeed, founded upon ordinal characters only, andnot upon class characters. This is particularly evidentwith the Rotatoria , the Somatotoma, the Turbellaria , theNematoidea, the Trematodea, and the Complanata, all ofwhich belong to the branch of Articulata. The Tunicata ,