Spectral-absorption coefficients of some porphyrins in the Soret-band region

colonies to establish themselves, 7, 10 and 21 days re- spectively, the bacteria were centrifuged and the culture medium was decanted. Part of each sediment of bacterial cells (0*5-10 ml.) was ground with fine sand and stirred with 2-3 ml. of 0.1N-HCI. After 1 hr. the supernatant liquid and the decanted culture medium were examined by paper chromatography. No canavanine was detected in either the cell extracts or the culture media. SUMMARY 1. Canavanine has been detected in the seeds of 11 species of leguminous plants.