Hence, then, after duly recognizing the fact that, as pointed out above, Life, even phenomenally considered, is not entirely covered by the definition, since there are various abnormal manifestations of life which it does not include, we may safely accept it as covering the normal manifestations--those manifestations which here concern us. Carrying with us the definition, therefore we may hereafter use it for guidance through all those regions of inquiry upon which we now enter. CHAPTER VII. THE SCOPE OF BIOLOGY. § 37. As ordinarily conceived, the science of Biology falls into two great divisions, the one dealing with animal life, called Zoology, and the other dealing with vegetal life, called Botany, or more properly to be called Phytology. But convenient as is this division, it is not that which arises if we follow the scientific method of including in one group all the phenomena of fundamentally the same order and putting separately in another group all the phenomena of a fundamentally different order. For animals and plants are alike in having structures; and animals and plants are alike in having functions performed by these structures; and the distinction between structures and functions transcends the difference between any one structure and any other or between any one function and any other--is, indeed, an absolute distinction, like that between Matter and Motion. Recognizing, then, the logic of the division thus indicated, we must group the parts of Biology thus:-- 1. An account of the structural phenomena presented by organisms. This subdivides into:-- _a._ The established structural phenomena presented by individual organisms. _b._ The changing structural phenomena presented by successions of organisms. 2. An account of the functional phenomena which organisms present. This, too, admits of subdivision into:-- _a._ The established functional phenomena of individual organisms. _b._ The changing functional phenomena of successions of organisms. 3. An account of the actions of Structures on Functions and the re-actions of Functions on Structures. Like the others, this is divisible into:-- _a._ The actions and re-actions as exhibited in individual organisms. _b._ The actions and re-actions as exhibited in successions of organisms. 4. An account of the phenomena attending the production of successions of organisms: in other words--the phenomena of Genesis. Of course, for purposes of exploration and teaching, the division into Zoology and Botany, founded on contrasts so marked and numerous, must always be retained. But here recognizing this familiar distinction only as much as convenience obliges us to do, let us now pass on to consider, more in detail, the classification of biologic phenomena above set down in its leading outlines.