Thymic epithelial tumors are rare and mostly malignant human neoplasms charac- terized by a fascinating variety of morphological features and an unrivaled frequency of associated autoimmune diseases. As a consequence, a myriad of complex diagnostic and clinical problems ensues in patients with these tumors. Since only a few specialists in each country are familiar with these problems, this volume intends to summarize the state of the art of thymic epithelial tumor pathology and biology and treatment protocols. The vol- ume is also designed to promote the interaction between scientists from a variety of disci- plines and physicians treating thymoma patients. In the first part of the volume, morphological and immunohistological criteria are given for the various subtypes of thymic epithelial tumors. The two competing classifica- tions and nomenclature systems existing to date are jointly considered. In addition. mor- phological overlaps between organotypic and nonorganotypic thymic epithelial tumors are stressed, since they may have a major bearing on diagnostic and therapeutic strategies. The second part of the volume is devoted to recent data on normal T-cell maturation and the impact of abnormal T-cell development in thymic epithelial tumors on the development of paraneoplastic autoimmunity. Multicolor flow cytometry. the human/SCI[}-mouse system, transgenic mouse technology, and T-cell cloning techniques have greatly contributed to this fascinating field of research.

Thymic epithelial tumors are rare and mostly malignant human neoplasms charac- terized by a fascinating variety of morphological features and an unrivaled frequency of associated autoimmune diseases. As a consequence, a myriad of complex diagnostic and clinical problems ensues in patients with these tumors. Since only a few specialists in each country are familiar with these problems, this volume intends to summarize the state of the art of thymic epithelial tumor pathology and biology and treatment protocols. The vol- ume is also designed to promote the interaction between scientists from a variety of disci- plines and physicians treating thymoma patients. In the first part of the volume, morphological and immunohistological criteria are given for the various subtypes of thymic epithelial tumors. The two competing classifica- tions and nomenclature systems existing to date are jointly considered. In addition. mor- phological overlaps between organotypic and nonorganotypic thymic epithelial tumors are stressed, since they may have a major bearing on diagnostic and therapeutic strategies. The second part of the volume is devoted to recent data on normal T-cell maturation and the impact of abnormal T-cell development in thymic epithelial tumors on the development of paraneoplastic autoimmunity. Multicolor flow cytometry. the human/SCI[}-mouse system, transgenic mouse technology, and T-cell cloning techniques have greatly contributed to this fascinating field of research.

ESSAYS IN JEWISH BIOGRAPHY by ALEXANDER MARX PmLADELPHIA THE JEWISH PUBLICATION SOCIETY OF AMERICA 5708-1947 TO THE MEMORY OF MY PARENTS GEORGE AND GERTRUD MARX Preface THE twelve biographies included in this volume were not written according to a plan. Most of them were called forth by anniversaries of great men others were intended as memorials to departed scholars whose names and achievements deserve to be retained in the minds of our own and future generations. Moreover, personal reasons also had a share in motivating my selec tion of each of these men, whose lives are here presented to a wider circle of readers. The four mediaeval scholars discussed herein, though not statesmen who influenced the course of history, left a lasting impression on the development of Judaism. The works of Rashi have attracted me since my early youth. My Talmud teachers, as well as Professor Adolf Berliner, my first teacher in Jewish History, imbued me with ad miration for Rashis rare personality and I have, in the course of my talmudic studies, gained in admiration for his wonderful Commentary on the Talmud. My interest in Saadia was aroused by the greatness and originality of his work and the unusual story of his life. It was sustained by the continued discoveries of new material in the Centra which changed and clarified the picture of this outstanding gaon. He was the pathfinder in a variety of fields which reached the culmination of their development in the works of that incomparable genius, Moses Maimonides. While the essays on these three intellectual giants were prepared in connection with their recent anniversaries, the paper on Rabbenu Gershom was written at the suggestion of Profes sor LouisFinkelstein for the Institute of Religious and Social Studies. It was difficult to get a clear picture of the x PREFACE before. Five of them were included in my Studies in Jewish History andBooklore, New York, 1944 but since that book was meant for a smaller circle of readers and its edition of 650 copies is entirely out of print, they are repeated here. This book is due to a suggestion made some years ago to The Jewish Publication Society by my friend, Profes sor Shalom Spiegel. I am very grateful to him and to the authorities of The Society for publishing this volume. Miss Anna Kleban was helpful with the preparation of many of these essays when they first appeared. Dr. Solomon Grayzel made numerous valuable suggestions in revising these papers for publication. I want to express my special thanks to my wife for her help, her encouragement and her constructive criticism. I have striven, so far as it is humanly possible, to pre sent an objective picture of each of the ancient and modern scholars, not permitting my personal feelings of admira tion or intimate friendship to blind my judgment. I hope that these biographies will find a friendly circle of readers and will serve, in spite of their simple and artless presenta tion, as a slight contribution to the study of Jewish history and the appreciation of some of our great scholars and sages. ALEXANDER MARX New York, December 1, 1947. TABLE OF CONTENTS PAGE PREFACE vii-x 1 RAB SAADIA GAON 3-38 2 RABBENU GERSHOM, LIGHT OF THE EXILE 39-60 3 RASHI 61-86 4 MAIMONIDES 87-111 5 MORITZ STEINSGHNEIDER 112-184 6 DAVID HOFFMANN 185-222 7 MAYER SULZBERGER 223-228 8 SOLOMON SCHECHTER 229-250 9 THE JEWISH SCHOLARSHIP OF JOSEPH JACOBS 251-254 10 HENRYMALTER 255-264 11 MAX LEOPOLD MARGOLIS 265-279 12 ISRAEL FRIEDLAENDER THE SCHOLAR 280-289 BIBLIOGRAPHY 293-298 ESSAYS IN JEWISH BIOGRAPHY 1 Rab Saadia Gaon, UTSIDE of Palestine no country has exerted a deeper influence on the development of Judaism than Babylonia. Jews had been settled there since the destruction of the first Temple. They had arranged for the return to the homeland under Cyrus they had inspired and financed the later group which returned under Ezras leadership and the trips of Nehemiah to strengthen the new Palestinian settlement...