54 SPECIALIZATION IN NATURAL SCIENCE. 



into one grand division treating of the inorganic por- 

 tions of the earth' s crust, and another treating of its or- 

 ganized life. The first has again ramified into miner- 

 alogy and geology, two very distinct branches, con- 

 nected, however, in an indeterminate way, by the study 

 of rock-masses, called lithology, or petrography. And 

 this, again, gives rise to a most novel, important, and 

 difficult specialty, microscopic petrography, or the 

 making and studying of thin microscopic slices of rocks. 

 In mineralogy, there are the departments of crystallog- 

 raphy and crystallogeny, mathematical and theoretical 

 studies of crystals, requiring for their mastery high 

 mathematical training and insight. In geology, we find, 

 as its chief divisions, physiographic geology, or the 

 study of the actual physical characteristics of the earth — 

 the life-study of such masters as Bitter, of Germany, 

 and our own Griiyot ; palaeontology, or the study of the 

 organic remains ; historical geology and stratigraphy, 

 or the study of the order of succession in the rocks ; 

 dynamical geology, the study of the action of the great 

 natural forces on the earth's crust. 



In that branch of natural history which treats of 

 organized beings, our modern subdivision begins with a 

 division which has been but recently generalized into a 

 specialty — if I may use such an expression — out of the 

 two subdivisions of botany and zoology. This is the 

 grand study of biology, or the facts and principles un- 

 derlying all life. Its two subdivisions are botany and 

 zoology. Botany has naturally resolved itself into its 

 two great branches of phsenogamic, or flowering life, 

 and cryptogamic, or flowerless life ; while the latter, at 

 least, in its sub-branches of algse, or sea weeds, fungi, 

 mosses, etc., furnishes several very absorbing and diffi- 

 cult lines of special study. 



The ramifications of zoology are almost bewildering. 

 The more important are in two classes. 



