For the last two decades biological science has been advancing at an almost meteoric speed. This collection of technical review papers summarizes some of the recent developments. The 19 articles were contributed by leading animal biologists to the XVI International Congress of Zoology in 1963. They cover the broad subject areas of genetic continuity, cell biology, development, evolution, phylogeny and behavior. The book is loaded with technical jargon and is primarily intended for the biological or medical scientist. As far as the general reader is concerned, this might as well be written in Bengali, but the volume will undoubtedly find a place in scientific book collections.