Zoology : an elementary text-book / [Sir A.E. Shipley].

  • Shipley, A. E. (Arthur Everett), Sir, 1861-1927.
Date:
1920
Catalogue details

Licence: Public Domain Mark

Credit: Zoology : an elementary text-book / [Sir A.E. Shipley]. Source: Wellcome Collection.

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    INTRODUCTION The word Zoology (Gr. £wov, an animal; Ao'yos, a discourse) denotes the science which concerns itself with animals, Life. . endeavouring to find out what they are and how they came into being. It is a branch of the wider science of Biology (Gr. /Ito?, life, Aoyos, a discourse)1, which deals with all living things, plants as well as animals. Before any progress can be made with the study of Zoology, it is necessary to get clear ideas on two points: firstly, as to what is meant by life and living things; and secondly, as to how an animal is to be distinguished from a plant. The idea implied in calling a thing living, is that in some respects its existence is similar to our own. Our own existence is the only thing immediately known to us, the standard with which we compare everything else. Every material object has certain points of resemblance to our bodies, inasmuch as all are composed of matter obeying the same laws of chemical affinity, gravitation, and so forth; it is necessary therefore to define the amount of re¬ semblance which constitutes life. Now everyone knows that human beings grow, that is, increase in size at the expense of matter called food, which is different from themselves—and that further, they give rise at intervals to fresh human beings. These two fundamental characteristics—the power of growth and of multiplication—define life; everything that can increase its bulk by building up foreign matter into itself and that reproduces its like is said to be alive. The idea originally underlying the word animal was a self- moving object as distinguished from a plant which was regarded as motionless2 and this distinction, is broadly speaking true. 1 This term is too well established to admit of alteration but it implies a mistranslation of /Stos. This does not mean ‘ life’ in the physiological sense but a period of life, a career, a life-time or circumstances of life, environment. 2 It is true that to all general statements of Zoology, as to this, exceptions could be found. The rule followed in this book is to have regard only to the 1 S. & M.