It is a source of great satisfaction to us that a Second Edition of this treatise should be called for, especially because it has given us the opportunity to produce, we believe, a better book. Eighteen chapters, amounting to one-third of the whole, are new, and of these, 13 deal with subjects not covered at all in the First Edition. We have paid more attention to embryonic and fetal growth, with chapters on cell differentiation (Lehtonen and Saxen), embryonic growth (O'Rahilly and Muller), control of fetal size (Snow), regulation of fetal growth (D'Ercole and Underwood), and ultrasonic...

Growth, as we conceive it, is the study of change in an organism not yet mature. Differential growth creates form: external form through growth rates which vary from one part of the body to another and one tissue to another; and internal form through the series of time-entrained events which build up in each cell the special- ized complexity of its particular function. We make no distinction, then, between growth and development, and if we have not included accounts of differentiation it is simply because we had to draw a quite arbitrary line somewhere. It is only rather recently that those...

Growth, as we conceive it, is the study of change in an organism not yet mature. Differential growth creates form: external form through growth rates which vary from one part of the body to another and one tissue to another; and internal form through the series of time-entrained events which build up in each cell the special- ized complexity of its particular function. We make no distinction, then, between growth and development, and if we have not included accounts of differentiation it is simply because we had to draw a quite arbitrary line somewhere. It is only rather recently that those...