EXPANSION AND ATTRACTION. 187 



tides to draw together into the form of dense masses, is, per- 

 haps, still more forcibly illustrated by the flint nodules found 

 in beds of chalk, and which are generally of a more or less 

 rounded form, evidently indicating an original state of solution 

 in the surrounding mass, from which they have become con- 

 densed, as they are now found. 



The first forms assumed by the vegetable materials that exist 

 in the world, were also diffuse and chaotic. Such were the 

 marine accretions of germinal slime, with their radical fibers, 

 and subsequent efflorescent, simple, and microscopic stems. 

 Several gradations of plants as they rise above these, are still 

 of imperfect exterior forms, of a loose and succulent nature, 

 and of an internal structure entirely cellular indicating, as 

 yet, but small progress in the condensive principle. In these, 

 however, the whole Vegetable Kingdom as one creation, has 

 its incipient and rudimental development. Further segrega- 

 tions and condensations of the vegetative elements are decid- 

 edly manifested in the subsequently formed terrestrial plants 

 possessing a vascular tissue and ligneous fiber. But as crea- 

 tion proceeds, still higher forms, possessing more marked and 

 widely diversified characteristics, are gradually developed, 

 until the flowering and dicotyledonous plants of the present 

 era came into being ; and these show the closest possible con- 

 nection of congenial, and the most perfect elimination of 

 heterogeneal vegetable elements. Hence, they exhibit the 

 ultimate degree of the Condensive and Expansive principle 

 which can be naturally applied to the Vegetable Kingdom. 



In the Animal Kingdom, including the human, the same 

 principles are distinctly operative ; and this, too, both with 

 reference to the individual organism, and the whole collection 

 of living beings. Professor Agassiz, who has investigated the 

 subject of embryology perhaps more thoroughly than any 



