vi INTRODUCTION 



up a position at opposite sides of the cell, a wall is formed, and 

 two cells result. These cells are known as daughter cells. 



A single cell may have permanent projections known as cilia 

 (hairs), and may be able to change its shape, by means of tem- 

 porary elongations known scientifically as Pseudopodia, or 

 temporary feet. It is wise to remember that single cells are 

 not imperfect, in fact they are far more adapted to their life 

 than some of the many-celled creatures. Nor is there any 

 justification in labelling amoeba and other Protozoa as the 

 beginning of life ; for we find that the amoeba, simple as it may 

 be, is dependent for food on organic matter. The organic matter 

 consists of living plants and the remains of decomposed plants 

 and animals. 



We can roughly divide pond life into 



large 

 small 



' microscopically large 

 small 



minute 



and plants into similar divisions. 



For example : the newt would be amongst the large, the 

 water-beetle amongst the small, whilst the water-mite, a 

 creature only just visible, would be classed as the very small. 

 With the aid of the microscope comparatively large animals will 

 be easily examined (such as vorticella), a higher power shows us 

 the amoeba, and a still higher power would give us a clear 

 picture of the smaller diatoms, &c. 



Just as the pond inhabitants vary in size so likewise does 

 their habitat. Some live in the mud at the bottom of the pond, 

 others on the lower branches of water-weeds, and many others, 

 again, are usually "at home" nearer to the surface. Our 

 equipment, therefore, must be such that we are able to collect 

 our creatures from any ordinary situation. The pond-hunter 

 needs no expensive appliances for his work ; all he requires he 

 can easily procure or make for himself, and if he should wish to 

 save time a very little outlay will buy the necessary equipment. 



Of course, just as in every other matter, if the pond-hunter 

 wishes to spend more on his appliances, he can always do so, 



