MOST adolescent boys and girls are more interested in themselves than in abstract problems. Although colleges emphasize mathematics and languages in their entrance requirements and say little about science, there has been a rapid growth in the number of sciences elected in the high [...] is primarily due to the realization that science is more a part of the lives of pupils than other school subjects and an answer to more of their [...] is more interested in making direct observations and reasoning from them than in abstract thinking. There is a concerted effort to ascertain the truth about phenomena and to find out how and why things happen. Science teaches a valid method of interpreting evidence and helps one to arrive at logical [...] most secondary schools throughout the country elementary biology or general science is taught in the first or second year. There has been a growing demand for an advanced course in general biology to follow the elementary science course. This text has been written primarily to fill this need. The emphasis of the book is on problems relating to human welfare.