Eakin, a Berkeley professor, has been jazzing up Zoology 10 for the last few years with a series of ""guest lectures"" impersonating the likes of Gregor Mendel, Charles Darwin,and Louis Pasteur. Assembling the costumes and working up the roles must have been great fun, and Eakin assures us that attendance and student interest have vastly benefited. But why the lectures have attracted so much public attention (international magazine coverage, speaking invitations, filmed versions) is a little hard to make out from the printed texts. One can surmise only that Eakin is an awfully fetching performer; the lectures themselves, pitched at the gentlest elementary level, are agreeable but less than riveting. Whether it's Harvey on the circulation of the blood, William Beaumont on the digestion, or Hans Spemann on the foundations of embryological organization, the format is the same. The great man introduces himself with a little lowkeyed autobiography and incidental atmosphere (a judicious ""Parbleu.!"" or Elizabethan locution, as the case may be), gives a brief account of his most notable discovery, and departs with a few beautiful thoughts on the true nature and role of science. (""And so the good scientist works, with fragments of truth, piecing them together carefully and critically . . . . "") It's all rather bland, but the photographs of Eakin in costume are delightful--we particularly love Mendel, wearing a cowled cape and an expression of fuzzy benignity, munching a handful of peas.