MacCracken, Helen Dolman. <br/><br/>
Science through discovery 2 / 
Helen Dolman MacCracken ; Donald Gilmore Decker and Mildred T. Ballou. 
 - New York :  The L.W. Singer,  C 1967. 
 - 166 p. :  ills. ;  24 cm. 
 - Singer Science Series. .
<br/><br/>329  329 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Science.<br/>Natural history.
<br/><br/><label>Dewey Class. No.: </label>508 / M26s