Overview and critique of stages and periods in canine development

Several aspects of CNS and behavioral developnient in relation to stages of development and the critical period of socialization in the dog are reviewed. Environmental and experiential treatments which may modify ontogeny are discussed. With particular emphasis on the specific and nonspecific effects of such treatment on the developing phenotype and the dependence or independence of a particular behavior or system upon stimulation, with or without which it may or may not develop. A more complete understanding of the evolutionary and developmental processes underlying the integrative development of the brain and behavior in different species is needed.