Characteristics of the absorptive surface of the small intestine of the chicken from 1 day to 14 weeks of age

The epithelial surface of the intertine of chicks 1 day to 14 weeks of age was examined with both scanning and transmission electron microscopes. Most of the intestinal villi were seen to be plate-like structures. During the first week post-hatch, goblet cell orifices were easily seen. Goblet cell pores were not readily apparent in the older birds. During this stage of early development discontinuity was seen among some epithelial cells. The villi of birds one week or older showed a more convoluted mucosal surface than the younger birds. Areas of cell extrusion were observed at the tips of some villi. The three dimensional cylindrical structure of the microvilli was shown with the scanning electron microscope.