LABORATORY MANUAL OF PHYSIOLOGY. 



CHAPTER I. 



BIOLOGICAL INTRODUCTION. 



Appliances. An aquarium; Slides; Cover glasses; Test-tubes; Pipettes; 

 Beakers; Microscope. 



SINCE the basis of physiology as well as morphology is the cell, 

 a few examples of the more common simple plant and animal cells 

 are here presented for study, as a preparation to the observation 

 of the physiologic phenomena accompanying the activity of the 

 more highly differentiated cell-groups of the higher animals. 



For this purpose, well-known representatives of the algae, fungi, 

 and protozoa have been chosen. 



I. ALG.E. 



These are plant cells of the lowest order, consisting, either of 

 single cells leading an individual existence, or of groups of cells 

 attached end to end so as to form filaments or threads. A green 

 coloring matter, chlorophyll, is common to the group. 



1. Protococcus. In the mud of shallow pools, ditches, and 

 roof-gutters, a unicellular form, Protococcus, may commonly be 

 found. This is seen, in the vegetative stage, as a spheroidal body, of 

 small size, having an outer tough transparent envelope, composed, 

 chiefly, of cellulose, and enclosing viscid granular protoplasm. 

 Certain portions of the protoplasm contain the coloring matter, 

 chlorophyll, which may be either green or red. These portions are 

 known as chromatophores. The cell contains a distinct nucleus 

 with a nucleolus. Reproduction takes place by the formation of 

 so-called zoospores. These are of two kinds, macro- and micro- 



