Metabolic investigations of premature and young infants have been hampered by difficulties in making quantitative urine and stool collections. Many studies have been limited to male infants and the duration of study has often been short, or interrupted by the development of skin irritation. Fragile or desperately ill patients who might benefit from investigation often are not studied because of the difficulties and hazards involved in available methods. A special pan designed after the type used in animal metabolic cages has been adapted for urine and stool collections from infants in incubators. This device has made possible the continuous collection of urine and stool for as long as 8 to 13 weeks. This metabolism pan has also permitted investigations of female infants as well as males and, further, has been found to be satisfactory and valuable in the treatment of the very small, sick or postoperative patient. See image in the PDF file Figure 1 is a sketch of the stainless steel pan and complete equipment with the infant in place. The pan is a shallow funnel with connecting tubing extending into a bottle below. The nylon netting is shown stretched tightly over the top of the pan and held in this position by metal rods, threaded through seams in the nylon and clamped in place outside the pan. The baby is placed prone or on his side on the netting with a bib under his head and a piece of nylon netting pinned loosely over his back or shoulders.