1. Homologies of positional information in thoracic imaginal discs ofDrosophila melanogaster

   • John L. Haynie

   OriginalPaper Pages: 293 - 300

2. Enzyme distribution patterns in the imaginal wing disc ofDrosophila melanogaster and other diptera

   • Th. E. Sprey
   • A. A. C. Eskens
   • D. T. Kuhn

   OriginalPaper Pages: 301 - 308

3. Thymic cell populations in amphibia: Quantitative study of the growth, stability, and regression of the cell populations in the thymus of the newtPleurodeles waltlii Michah

   • Yehia Moustafa
   • Pierre Chibon

   OriginalPaper Pages: 309 - 319

4. Primitive streak-forming cells of the chick invaginate through a basement membrane

   • Eduardo Mitrani

   Rapid Communication Pages: 320 - 324

5. A densitometrical method for the study of pattern formation in a ciliateChilodonella

   • Janina Kaczanowska
   • Leonora Wychowaniec
   • Marek Ostrowski

   Rapid Communication Pages: 325 - 330

6. Preblastoderm mosaics of mutants of the bithorax-complex

   • F. J. Miñana
   • A. García-Bellido

   Rapid Communication Pages: 331 - 334

7. Gap junctions are non-randomly distributed inDrosophila wing discs

   • Jan Stephen Ryerse

   Rapid Communication Pages: 335 - 339