This volume comprises normal tables (description of normal development) for protozoa and invertebrates widely used in developmental biology studies. The species chosen reflect their advantages for laboratory studies, the information avail able, and their availability for experimentation. Chapter 11, which contains the normal tables for the starfish Asterina pectinifera, was written specially for this edi tion, which is the invertebrate section of the revised and augmented translation of Ob"ekty Biologii Razvitiya published in Russian in 1975 as a volume in the series of monographs Problemy...

Studies of oogenesis occupy an important place in current in vestigations in developmental biology. Today no one has any doubt whatsoever that oogenesis is not just the prelude to development, but is development itself, and a very essential part of it. These words of an eminent Soviet scientist, B. L. As taurov, taken by T. B. Aizenshtadt as an epigraph to her chapter in this book, make a good epigraph for the entire book. It is now clear that during oogenesis not only vast reserves of ribosomes and mitochondria, of yolk, carbohydrates, and lipids, and of enzymes for protein and nucleic acid...