This volume was originally intended to be an English translation of the book MetllOden in der medizinischen Cytogenetik, published in 1970. Just about then, however, a number of new techniques were introduced in human cytogenetics and soon acquired the utmost importance, parti cularly in clinical diagnosis, so that the English edition had to be con siderably enlarged. As a result, there are now twelve chapters instead of eight, and two additional authors have been called upon, Dr. KRONE and Dr. SCHNEDL. In addition to the up-to-date presentation of con ventional methods of cell culture and techniques for the preparation and identification of human chromosomes, this text covers the various tech niques of producing banding patterns and applying them in chromo some identification. Further, it deals with the culture of amniotic fluid cells and gives instructions for handling tissue-culture cells for bio chemical analysis; it thus meets the ever-increasing requirements of a modern cell-culture laboratory. To paraphrase the aims of this book, we quote part of the preface to the German edition: "It was intended to collect the various methods so as to make them accessible for laboratory use. Furthermore, it is hoped that the reader faced with current research problems will be stimulated to modify and supplement the techniques described, instead of merely applying them automatically. In a rapidly developing field, some methods are still preliminary, and no final presentation seems possible."

Upon wresting the control of the earth from the Titans, Zeus assigned the task of creating living creatures to two Titan brothers who had sided with him in the epic battle just concluded. Because Epimetheus, who had been endowed only with hindsight, had the first hand in this creation, all the good attributes were exhaus ted by the time the lion, the elephant and other animals were created. When the time came for the creation of man, there were precious few materials left to work with. Not surprisingly, man was made weak and naked. Prometheus took pity on this miscreation and gave man the use of fire. For this foresight, Zeus meted out horrible punishment, binding Prometheus to a rocky pillar in the Caucasas Moun tains and letting a vulture consume his liver daily. It seems to me that the ancient Greeks in their unfathomable wisdom under stood the essence of the evolutionary process very well. Had Escherichia coli of 200 million years or so ago been endowed with the foresight to anticipate the eventual emergence of and subsequent dominance by mammals of this Earth, they would no doubt have equipped themselves, in anticipation of the coming cer tainty, with the lac operon to deal with lactose in the suckling mammalian infant's gut. Had they been able to do so, the actual emergance of mammals would have exerted no selective pressure upon existing E. COLI."

Seit der Entdeckung, daB Chromosomenaberrationen die Ursache fiir angeborene Entwicklungsstorungen beim Menschen sein konnen, gelang es in den letzten 10 Jahren, immer mehr Krankheitsbilder cytogene- tisch zu charakterisieren. Cytogenetische Methoden sind so zu einem unentbehrlichen Instrument in der klinischen Diagnostik geworden. Die Absicht des vorliegenden Buches ist es, diese viel- faltigen Methoden zusammenzustellen und fur den Laboratoriumsgebrauch ubersichtlich zuganglich zu machen. AuBerdem soll die Lektiire auch an offene Probleme der Forschung heranfuhren und dazu an- regen, die Methoden nicht nur schematisch nachzu- arbeiten, sondem standig experimentell zu variieren und zu erganzen. Auf einem Gebiet, das sich in einer so vielseitigen Entwicklung befindet, haben manche Methoden allerdings einen noch vorlaufigen Charakter, und eine abschlieBende Dbersicht ist nicht immer moglich. Es ist zu hoffen, daB die von dem Buch ausgehenden Anregungen dazu beitragen werden, die Methoden der menschlichen Cytogenetik zu bereichem. Bonn und Freiburg i. Br., im Januar 1970 H. G. Schwarzacher U. Wolf v Mitarbeiterverzeichnis Herausgeber: Professor Dr. HANS GEORG SCHW ARZACHER Anatomisches Institut der Universitat 5300 Bonn NuBallee 10 Privatdozent Dr. ULRICH WOLF Institut fiir Humangenetik und Anthropologie der Universitat 7800 Freiburg i.Br. AlbertstraBe 11 Mitarbeiter: Dr. WOLFGANG GEY U niversitats-Kinderklinik 8000 Miinchen 15 LindwurmstraBe 4 Professor Dr. SUSUMU OHNO Dept. of Biology, City of Hope National Medical Center Duarte, CA 9lO10 /USA Privatdozent Dr. EBERHARD PASSARGE Institut fiir Humangenetik der Universitat 2000 Hamburg 20 MartinistraBe 52 Professor Dr. RUDOLF ARTHUR PFEIFFER Institut fiir Humangenetik der Universitat 4400 Miinsteri. Westf.