Quantitative aspects of the embryonic growth of the intestine and stomach.

The increase in the volume of the intestine and stomach with time was estimated in mouse embryos by means of a morphometric technique. The specific growth rate of the intestine is constant until birth, whereas that of the stomach decreases by a constant amount in time. Evidence is given that the growth of both these organs is a continuous process in the period under study; growth models based on exponential phases separated by breaks were not confirmed. A methodological criticism relating to the effect of skew sectioning in the estimation of the intestinal length and cross sectional area is put forward.