MUCH HAS been said about the appropriate grade placement of biology. We also find much written. Some of the better articles are indicated in the ref erences. Sharkan (5) indicates, in general terms, the pros and cons of presenting biology at the ninth grade level. His conclusions bring out the need for additional research to substantiate placement of bi ology at either the ninth-grade level or at the tenth grade level. One of the early articles on the subject was by Goldstein (1), who concludes: I do not think that high-school freshmen are mature enough to study biology, at least not the biology we teach in New York City. He also reports that on test scores in the New York State Regents Examination, his clas ses scored as follows: In his ninth-year biology course, ten out of 32 of the pupils (31.3 percent) scored above the median of the total group, while in his tenth-year biology course, 25 out of 38 scored above the median of the total group. M?tala (3) gives opinions on when to teach biol ogy, and also suggests questions which must be an swered: I doubt that anyone will question that a biology course can be taught ninth graders with success, or that ninth graders can do as well as tenth graders in many cases and with many types of courses. But there are questions that would like to raise--loudly and long. s this the biology we want the potential scientists to have? Mathes and Blanc (4) reported on a study which involved most of the students taking biology in junior and senior high school during the second semester of the 1958-59 school year in Denver, Colorado schools. Their findings: point out clearly that the group of ninth graders selected on the basis of a bility, interest in science, and teacher's recom mendations did considerably better than uns elected high school students. When compared with a group of tenth-grade students selected to match the ability of the ninth grade, ninth-grade students did slightly better than the tenth-grade group. Heidegerd (2) reported on his doctoral thesis completed at the University of Illinois. His conclu sions were: It would seem that the change to ninth-grade biology and tenth-grade physical sci ence should only be made if it is expected that there will be some loss in biology achievement and that other gains will make the change worthwhile. After reading a variety of studies and bringing together all findings, it would appear that more research is needed. Hence, the following report is given to add additional information which may prove useful in helping a school system to decide on the grade placement of high-school biology. This study involves the administration of an a chievement test to students in two different types of situations. The first group was made up of ninth graders who had completed a year of biology. The second group was made up of tenth graders who had completed a year of biology. Schools in which the tests were given are in central and eastern Pennsylvania. Because of the predominance of the 6-3-3 plan of organization of our schools, it is dif ficult to find teachers who are responsible for both ninthand tenth-grade biology. This is one prob lem which could not be overcome in designing the research project. In other words, it was not pos sible to compare performance of students, both ninth graders and tenth graders, working with the same teacher. The Cooperative Biology Test, Form Y, distrib uted by the Educational Testing Service, was the achievement test used in the study. Test forms, answer sheets, and instructions were mailed to each cooperating teacher in the early spring months prior to the June testing period. In June, the tests were administered by each teacher. The complet ed answer sheets were mailed to the author, who scored them and mailed a copy of the results to the cooperating teachers. Data thus collected were used in the study. These data are reported in Table I. These data serve only as introductory material. If we consider both groups as total units, then the data are, at least, interesting. We note that the ninth graders scored somewhat higher on the aver age on the Otis Quick Scoring Intelligence Test. However, their mean score on the Biology Achieve ment test was two points lower than the mean score of the tenth graders. Whether these differences are significant is problematical. Seven of the eleven classes of ninth graders were composed of