Intersexuality In The Animal Kingdom

When Richard Goldschmidt' coined the term "intersexuality" in 1915, he intended it to apply to normally dioecious species which exhibit some kind of mixture between male and female characters. However, as knowledge of the bewildering variability present in the sexual orga nization of members of the animal kingdom has increased, the original meaning of the word has changed. Today many authors define inter sexuality as "the presence of both male and female characteristics, or of intermediate sexual characteristics, in a single individual".2 This more extensive and widely accepted concept justifies the title of our book •. Among all the anatomical and physiological features of living organisms the reproductive system has a unique importance for the perpetuation of the species. Conversely, reproductive processes are of little or no account for the viability of the individual. Therefore, within the framework of general biology reproduction has all too often been looked at solely from the point of view of genetics. Lively discussions about genotypic versus phenotypic sex determination long dominated the sci entific literature on sexuality in animals; this one-sided emphasis has tended to obscure many important facets of an organism's ability to reproduce. Recent developments in current biological research have brought the classic problem of sex differentiation into focus again, and the rapid progress being made in comparative endocrinology has added a new di mension to the study of reproductive biology.

The subject of this book is neuroendocrinology, that branch of biological science devoted to the interactions between the two major integrative organ systems of animals-the endocrine and nervous systems. Although this science today reflects a fusion of endocrinology and neurobiology, this synthetic ap proach is relatively recent. At the beginning of the 20th century, when the British physiologists, Bayliss and Starling, first proposed endocrinology to be an independent field of inquiry, they went to great lengths to establish the autonomy of chemical secretions in general and their independence from nervous control in particular (Bayliss, W. M. , and Starling, E. H. , 1902, The mechanism of pancreatic secretion,]. Physiol. 28:325). They argued with Pav lov, who said that there was a strong influence of the nervous system on the gastrointestinal phenomena the endocrinologists were studying. For several decades, the English physiologists prevailed, at least in the West; and Pavlov's critique was not taken to heart by the practitioners of the newly emerging discipline of endocrinology. Through the work of Harris, the Scharrers, Sawyer, Everett, and others, there has been something of a scientific detente in the latter half of this century; the hybrid field of neuroendocrinology is now regarded as one of the corner stones of modern neural science and is of fundamental importance in basic and clinical endocrinology.

Advances in the Study of Behavior