Abstract
The organophosphate Malathion produces malformations in the limbs of chick embryos. Staining with buffered toluidine blue reveals abnormal areas in the cartilage characterized by hypertrophy of the chondroblasts, lack of ground substance, and weak (gamma) γ metachromasia. Radioautography with S35 shows little incorporation into the chondroitin sulfates of the cartilage ground substance.