For many years Professor KOLLER has possessed an international reputation in the fields of cytogenetics and karyology, both in their fundamental aspects and in their relation to the problems of tumour causation, especially to the role of heteromromatin, and few men have made a greater contribution. The role of the mromosome complex in carcinogenesis has exerted a natural fascin ation for many decades, but there can be little doubt of the great advances in know ledge and understanding whim have accrued of recent years. Although it is probable that the key event in the inception of particular tumours resides in a delicate molec ular rearrangement, and is hence undetectable by conventional microscopical methods, nevertheless a large proportion is accompanied by karyotypic variation and relatively gross changes in mromosomal number, order and arrangement, witness tlie discovery of the Philadelphia mromosome and its consequences. Further, any such manges in the mromosomal apparatus must inevitably be attended by profound repercussions in the cytoplasm with all that this must mean in protein synthesis and cellular behaviour.

Inhalt
1 Chromosome Structure and Function.- Summary.- 2 Chromosomal Anomalies as the Cause of Developmental Disorders.- 1. Numerical Changes.- 2. Structural Changes.- 3. Chromosome Anomalies in the Foetus.- 4. Chromosomal Mosaicism.- Summary.- 3 Mitotic Anomalies in Tumours and Boveri's Theory.- Summary.- 4 Malignant Cell Populations and the Stemline Concept.- Summary.- 5 Chromosomal and Functional Differences in Malignant Cell Populations.- Summary.- 6 Primary Tumours in Animals.- 1. Spontaneous Primary Tumours.- 2. Induced Primary Tumours.- Summary.- 7 Chromosome Aneuploidy in Human Malignancies: Effusions.- Summary.- 8 Chromosome Aneuploidy in Human Malignancies: Solid Tumours.- Summary.- 9 Marker Chromosomes and the Clonal Evolution of Chromosome Aberrations.- Summary.- 10 Chromosomes in Precancerous Lesions and in Tumour Development.- Summary.- 11 Chromosomal Predisposition to Cancer.- Summary.- 12 Chromosomes and Viral Oncogenesis.- Summary.- 13 Chromosomes and the Treatment of Cancer.- Summary.- Conclusion.- References.