White Leghorn eggs were injected on the 15th day of incubation with various doses of an acqueous extract of Solanum malacoxylon (SME). Most of the embryos died after the injection of 0.2 ml but the dose of 0.1 ml was well tolerated. The concentration of calcium in the sera from 15-day embryos injected with 0.1 ml SME was determined. Three hr after the injection the concentration of calcium had increased significantly; this increase lasted for at least 3 hr more but had disappeared 12 hr after the injection. It is suggested that this hypercalcemia may be produced by a water-soluble analog of 1,25-(OH)2D3 the presence of which has been demonstrated in the SME by other authors. It is also assumed that the mortality produced by the higher doses may be related to the hypercalcemia.