DEFINITIONS
REMARKS ON THE HISTORY OF THE SUBJECT
- A. Small Groups of Galaxies
Clusters of Galaxies
Recent Advances
Instrumentation
WIDELY SEPARATED INTERCONNECTED GALAXIES
- The Triple System IC 3481, Anon, IC 3483
KEENAN's System
Another Remarkable Filamentary Structure
WILD'S Triple Galaxy
The Basic Types of Structures
Some Conclusions
LONG EXTENSIONS AND SPURS OF SINGLE AND OF MULTIPLE
GALAXIES
- NGC 4038-4039
NGC 750-751
A System in Leo
NGC 4651 and Dwarf Companion
NGC 3628 and Faint Extensions
Spiral Galaxy with One Long Arm
SOME SPECIAL PROBLEMS
- The Milky Way System and the Magellanic Clouds
The Andromeda Nebula and its Companions
New Clues on the Sense of Rotation of Spiral
Galaxies
Multiple Galaxies in Clusters and in the General
Field
OUTLOOK AND PROGRAMS
REFERENCES
