T.H. Morgan at Caltech: a reminiscence.

AT the urging of Professor G. M. McKinley, who sophila genetics had become too complex for him. Mortaught genetics at the University of Pittsburgh, I gan was a discoverer, not a bookkeeper, and after the applied for graduate school at Caltech, was accepted, basic findings of Drosophila genetics had been made, he and arrived in Pasadena for the opening of the fall term left the subject in the competent hands of his students of 1936. It would never have occurred to me to go to Sturtevant, Bridges, and Muller (and Mrs. Morgan) and a school so far away—3 days by train, in distant Califormoved on to other fields. When I came to know him, nia—had it not been for Dr. McKinley, but this was only he was working on a genetic problem in the primitive the first of a series of lucky choices that formed my marine chordate, Ciona. On most weekends, Morgan career. and Tyler went to the Kerckhoff Marine Laboratory at On arriving at the Caltech campus and locating the Corona del Mar, California, a little over an hour’s drive Kerckhoff Laboratory of Biology—a building so grand from Pasadena. Being Tyler’s graduate student, I would in my eyes that I felt the need to ask a passing student if now accompany them. this was indeed the home of the biology department—I As an undergraduate, I had done some research on entered and found the office of the Chairman, Thomas transplantation in salamanders that had resulted in an Hunt Morgan, on the second floor. I identified myself article in the Journal of Experimental Zoology, and this, to Morgan’s fearful secretary, Miss Brusstar, and was combined with the fact that I had indicated no preferred ushered into Morgan’s office. I recognized him immedifield of graduate study in my application, had no doubt ately from photographs published in 1933, when he determined Morgan’s decision to send me to work with won the Nobel Prize. My first encounter with this man Tyler. These events now afforded me the opportunity who was to have a large influence on my life was brief. to become more than casually acquainted with Morgan. I stood in front of his desk, and Morgan looked up at The three of us would leave Pasadena at about nine me from a stack of papers in front of him. “Horowitz,” o’clock on Saturday morning in Tyler’s Model-A Ford, he said, “you are going to work with Albert Tyler.” He with Tyler at the wheel, Morgan in the front passenger then directed me to Tyler’s office. I had never heard seat, and me in the back. We proceeded to the Newport of Albert Tyler, but at the moment I was not inclined Beach Yacht Club, a few miles up the coast from Corona to ask questions of Morgan, and I went off dutifully to del Mar. The pilings there were the home of a large find Albert Tyler’s office. population of Morgan’s experimental animal, Ciona, I soon learned that Tyler was an embryologist—what an ascidian. We would pull a sufficient number of them today would be called a developmental biologist. He off the pilings and take them with us, in a bucket of worked on the early development of sea urchins and seawater, to the marine station. other marine invertebrates. He had been Morgan’s stuCiona is hermaphroditic, but self-sterile. The rule is dent at Columbia University and had come to Pasadena that the sperm of a given individual do not fertilize the with the Morgan group in 1928, when the Biology Divieggs of the same individual, but are fertile with the eggs sion at Caltech was founded. I soon learned that Morgan of all other Ciona. Occasional exceptions are found. had long since given up working with Drosophila and Morgan perceived here a genetic problem and set himhad returned to an earlier love, marine animals. Droself the task of learning what he could about it. At the marine laboratory, he would set up several experiments, each consisting of a square array of Syracuse dishes containing seawater, 5 to 10 dishes on a side, in which This essaycommemorates the 70th anniversaryof thefoundthe sperm and eggs from 5 to 10 individuals were crossed ing of the Division of Biology at Caltech by Thomas Hunt Morgan in 1928. in all possible combinations. In some experiments,