Each year, 20 students (10 to be supported by NSF REU funds, and 10 to be supported by local funds) will be selected from colleges and universities around the country to spend a ten week period between early June and mid-August at Washington University, in order to engage in intensive developmental-biology research under the guidance of one of the more than 50 potential faculty mentors. The emphasis of the program will be on getting all of the students quickly engaged in interesting research projects in active, productive laboratories, and on aiding them to move as quickly and as far as possible in the direction of becoming independent research investigators. However, the students will also be provided with an assortment of supplemental activities designed to aid them in developing other aspects of their scientific personae; these will include: (i) A series of weekly seminars and workshops led by faculty, in which students will be introduced to the leading model systems, methods and paradigms of modem developmental biology. (ii) An overnight retreat devoted to discussion of issues and problems in research ethics will be held at nearby Meramec State Park in the second week of each summer program. (iii) A follow-up to the retreat will occur at the bi-weekly Ethics Forum, in which participants grapple with issues in research ethics raised by scenarios prepared by a different group of students each time. (iv) In alternate weeks these student meetings will be devoted to a Developmental Biology Journal Club. (A graduate student with appropriate interests and experience will serve as organizer and moderator of these two kinds of weekly meetings.) (v) The program will conclude with a day-long Undergraduate Research Symposium, in which each of the participants will make a presentation summarizing her/his summer's research accomplishments.