PROBLEM 3. How Cells Are Arranged in A'tmiials and Plants 135 



with two needles. Add a drop of Ringer's solution and a cover slip. Note 

 the muscle fibers with their light and dark bands. Add a drop of aceto- 

 carmine stain to one edge of the cover slip and draw it under the cover 

 trlass by holding a piece of blotter at the opposite edge. Note the many 

 elon^^ated nuclei within each fiber. Draw what you see. (^) liivohnitary 

 or smooth. With your scissors remove a small piece of the stomach of 

 the frog. On this piece separate the inner coat from the outer coat with 

 your needles. Lay the outer coat on a slide and tease apart the cells 

 of the thick outer coat of muscle. Stain with aceto-carmine and add a 

 cover slip. Observe the long thin cells, packed closely together. Do you 

 see the long nuclei? How do these cells difi^er from the voluntary muscle 

 fibers? Draw. 



Blood Tissue: Place a drop of blood on your slide and add a cover slip. 

 What shape are the red blood cells? Do they have nuclei? Draw. 



Further Activities in Biology 



1. A viseful project is the preparation of models of different kinds of 

 tissue cells. These models can show the shape, relative size, and special 

 characteristics of the cells. 



2. By using a magnifying glass and a scalpel, try to learn something 

 about plant tissues. Can you distinguish difi'erent tissues in a young stem? 

 Examine a thick leaf for tissues. Describe what you see. If you have a 

 microscope you may be able to see some of the cells after teasing some 

 of the tissues farther apart. 



/// UNIT III yon will consider these problems: 



Problem i . What Part Do Leaves Play in Making and LTsing Food? 

 Problem 2. What Part Do Roots and Stems Play in ALiking and 

 Using Food? 



