1846.] Structure and Classification of Zoophytes. 259 



STRUCTURE AND CLASSIFICATION OF ZOOPHYTES. 



By James D. Dana, A. M., Geologist of the United States Ex- 

 ploring Expedition during the years 1S38, '39, '40, '41, '42. 

 Philadelphia: Lea & Blanchard. 1846. pp. 132. 



In a philosophical point of view, the lower forms of life are 

 more interesting than the higher. It is in these, that life is ac- 

 companied with the simplest apparatus, and here too, it is less en- 

 cumbered wnth complex conditions. In the higher circles of 

 organization, functions are specialized, and the organs by which 

 they are executed are as complicated as though they were inde- 

 pendent machines and moved by their own inherent powers. 

 Notwithstanding this, they act together under the influence 

 of one controlling power, which presides over and unites all 

 parts and all functions into one system; hence the multiplied 

 and complex relations which are established by the structure 

 and organization itself, produce necessarily numerous reactions 

 in parts distant from those in which the disturbing causes 

 may have been applied. We cannot, therefore, study the phe- 

 nomena of life and organizations under such complicated con- 

 ditions with as much confidence in the results as in those simple 

 and less complex forms. There is too, in the higher grades far 

 less tenacity of life; and the hold which the vital principle has 

 upon the organization is so slight, that it is extinguished by a 

 breath. It is like the union which exists in the complex products 

 of organized bodies, which requires only presence, to induce cata- 

 lyctic actions, when the whole combination of atoms is dissolved: 

 or, it is similar to the arrangement of atoms in Prince Rupert's 

 drop; make but the slightest solution of continuity, and instantly 

 all that remains of a well-formed sphere of glass is a heap of 

 unorganized sand. Zoophytes, however, are more like the simple 

 molecule, they resist changes and bear up under vicissitudes which 

 would destroy the higher organizations; and hence experiments 

 designed to show the relation of organs and fianctions may be in- 



