International Review of General and Experimental Zoology, Volume 4 discusses the epibranchial organs in lower teleostean fishes, an example of structural adaptation; the aging and regression in the colonial marine hydroid Campanularia flexuosa, with special reference to senescence in hydroids; and the structure and characteristics of avian egg shells. The text also describes tissue mast cell and wound healing; the quantitative aspects of neurohistology; and the concept of the rods and cones approach. The strong relationships between the feeding behavior of marine organisms and biological conditions expressed in evolutionary terms are also considered. Zoologists, physiologists, biochemists, and people involved in the study of fish and wildlife services will find the book invaluable.