1. Fine structure studies on phragmoplast and cell plate formation

   • Andrew Bajer

   OriginalPaper Pages: 383 - 417

2. Factors involved in the expression of gene activity in polytene chromosomes

   • H. D. Berendes

   OriginalPaper Pages: 418 - 437

3. The replication of human heterochromatin in serial culture

   • Jean H. Priest

   OriginalPaper Pages: 438 - 455

4. The karyotype of some Australian species of Macropathinae (Gryllacridoidea — Rhaphidophoridae)

   • Alejo Mesa
   • Amilton Ferreira
   • R. S. de Mesa

   OriginalPaper Pages: 456 - 466

5. Chromosome number in the lizard genus Uta (family Iguanidae)

   • Lewis A. Pennock
   • Donald W. Tinkle
   • Margery W. Shaw

   OriginalPaper Pages: 467 - 476