8 FIRST LESSONS IN ZOOLOGY. 



Before studying this book we earnestly advise the student 

 to read the account of the anatomy of the fish, and also 

 study the skeleton and, dissect a perch or any common fish. 

 The student will thus have a standard of comparison, a 

 standpoint from which to survey the animal world as a 

 whole. He will thus learn the relations of the skeleton or 

 solid framework of an animal to the muscles, etc., and learn 

 what a heart, lung, or eye is. Then he can the better un- 

 derstand the structure of the lower animals. 



Moreover we should study how the fish swims, how its 

 heart beats, or its eyes see. This is studying the Physiolo- 

 gy of the animal. Then we should learn how the animal 

 grows or develops from the egg, and this is called Embryol- 

 o(///, the germ of an animal being called an embryo. The 

 bodies of animals are made up of cell*. A cell is a micro- 

 scopic mass of protoplasm. Animalcules are composed of 

 but a single cell; such creatures are said to be nnicdlnltr, 

 but most animals are formed of bone, cartilage, muscles, 

 nerves, etc. These parts are made up of cells. Hence 

 these animals are many-celled. The cells form tissitex, 

 such as muscular or nervous tissue. The study of cells and 

 tissues is called Histology. Finally, we should acquaint 

 ourselves with the habits and mental traits of the animal, 

 and this is called Psychology. 



A fish is the most convenient vertebrate for use in ordi- 

 nary school laboratory work. The object of these lessons is 

 to induce the scholar to depend as far as possible upon the 

 use of his own eyes and brain. He should observe with 

 care some of the common animals here described, most of 

 which he can readily obtain, and then study their form, 

 habits, and the leading features of their anatomy. After 

 examining a jelly-fish, star-fish, clam, lobster, insect and 

 fish, and reading about their mode of growth, he will ob- 

 tain a knowledge, however elementary, of the principal 

 groups of the animal kingdom which he will remember 

 throughout life. 



