The correspondents are:
Dr Edmond Gabbay, Salvatore Gambino, Dr George Gamow, Dr Clelia Ganoza, Jack Gardiner, Dr Erhard Geissler, Dr Santiago Genovés T, Karl Geyer (in German), Dr Dhanjoo N Ghista, Dr Ian Gibson, Dr Oliver Gillie, A Glasby (Glasby Hygiene Research), Dr Alfred L Goldberg, Professor James A Goldman (Abraham Joel Tobias), Philip Goldstein (Genetics Made Easy), Dr Brian Goodwin (Gerhard D Wassermann), J R Gordon (A Revai & Co Ltd, order for Nucleic Acid and Protein Kits), Dr Richard Grantham, Dr Irving Gray, Professor Melvin Greenblatt, Dr Jay E Greene (McGraw-Hill Encyclopedia of Science and Technology), Dr Geoff Grigg, , Dr François Gros, Professor Hans Grüneberg, Dr Marianne Grunberg-Manago, Dr Richard Guillemin (including Guillemin et al, "Isolation, molecular structure and synthesis of the hypothalamic hypophysiotropic TSH-releasing factor (TRF) of ovine origin"), Dr J B Gurdon, Dr H Gutfreund, Bernard Guyer ("Watson and Crick or the rape of DNA"), and Andrew Gyles (including Gyles, "Expression of genes in eucaryotic cells - a model").
One letter in German (Geyer).