As the name implies, the mammary gland is the distinguishing feature of mammals. The mammary gland is part of the reproductive apparatus, and lactation is the final phase of reproduction. In most mammals it is an essential phase, and failure to lactate, like failure to ovulate, means failure to reproduce.

Fossil evidence suggests that mammals arose from certain therapsid reptiles some 200 million years ago; unfortunately the soft tissues are usually not preserved in fossils so we do not know when mammary glands first appeared during the course of evolution. Lactation bestowed considerable advantages on the mammalian mother over her viviparous reptilian counterpart, since it ensured an ideal diet for the young after birth; reptiles on the other hand might have had to migrate to special areas where the young could find the type of food that they required. It has even been suggested that the decline of large reptiles at the end of the Mesozoic may have been due to climatic and floral changes that reduced the type of food required by their young. Lactation also permitted birth of an animal with an immature skull and jaws, since teeth are not required for suckling; by the time weaning occurred, and teeth became essential for feeding, the jaws could be sufficiently developed to accommodate a nearly complete set of opposable teeth.

In this, our Second Edition of Reproduction in Mammals, we are responding to numerous requests for a more up-to-date and rather more detailed treatment of the subject. The First Edition was accorded an excellent reception, but the Books 1 to 5 were written ten years ago and inevitably there have been advances on many fronts since then. As before, the manner of presentation is intended to make the subject matter interesting to read and readily comprehensible to undergraduates in the biological sciences, and yet with sufficient depth to provide a valued source of information to graduates engaged in both teaching and research. Our authors have been selected from among the best known in their respective fields.

Book 3 discusses the manifold ways in which hormones control the reproductive processes in male and female mammals. The hypothalamus regulates both the anterior and posterior pituitary glands, whilst the pineal can exert a modulating influence on the hypothalamus. The pituitary gonadotrophins regulate the endocrine and gametogenic activities of the gonads, and there are important local feedback effects of hormones within the gonads themselves. Non-pregnant females display many different types of oestrous or menstrual cycles, and there are likewise great species differences in the endocrinology of pregnancy. But the hallmark of mammals is lactation, and this also exerts a major control on subsequent reproductive activity.

From the Preface to the First Edition

Reproduction in Mammals is intended to meet the needs of undergraduates reading Zoology, Biology, Physiology, Medicine, Veterinary Science and Agriculture, and as a source of information for advanced students and research workers.

This book has grown out of the requests by many users of FloraEuropaea (Tutin et al., 1964, 1968, 1972, 1976, 1980) for information on the sources of the chromosome numbers cited in that work. During discussions about the publication of these data it became apparent that there is also a demand for a basic checklist of the taxa recognised in the Flora, and that these two requirements could readily be met in the same volume.

The Checklist

Apart from the fundamental value of FloraEuropaea to all modern taxonomic studies of European plants, the names and sequence of taxa it presents are widely used for arranging herbaria and libraries concerned with these plants. It is intended that the handy format of this checklist will facilitate these latter activities, as well as being useful in recording and assessing local floras within Europe.

The sequence of taxa is exactly the same as that used in FloraEuropaea except that the Rubiaceae, which for technical reasons had to be published in volume 4 rather than in volume 3, have been positioned correctly in the Checklist. All species and subspecies ‘accepted’ in FloraEuropaea (i.e. those prefixed by a number or a letter) are included here. Those unnumbered taxa of doubtful status are only included if a chromosome number is given for them in FloraEuropaea, as is also the case for the agamospecies (‘microspecies’) listed, but not described, within the ‘species-groups’ of apomictic or partially apomictic genera.

An institutional anniversary provides the occasion to stand back from the transient pre-occupations of administration, teaching and research, and look at the tradition in which the particular institution operates. In my own case, several factors have coincided to make the process especially congenial. The first, and most important, is very personal, and concerns my attitude to history. Twenty years ago, the suggestion that I should write a book on the history of the Botanic Garden, or of Cambridge botany, would have worried and even depressed me: now I find the opportunity richly rewarding. I can only report this change of heart without comment.

A second factor is the product of my career as Curator of the Herbarium and Lecturer in the Botany School, from which I was appointed in 1973 as Director of the Garden. This translation from a professional career in scientific botany in the main University Department to my present post enables me to appreciate the separate and combined elements in two interestingly different traditions, and stimulates me to ask how the differences came about. To some extent, this book is a product of such questioning.

The third of the factors encouraging me to write this little book concerns the nature and size of the University Botanic Garden itself. An institution occupying under 40 acres and employing fewer than 40 people is a comprehensible whole, in which it is possible to feel personal links and loyalties and to understand the nature and strength of tradition.