There were two substances isolated from the culture filtrate of this mould, one had a “fumigatin” (3 hydroxy-4 methoxy-2:5-toluquinone.)17) -like activity against microorganisms, and the other was identical with spinulosin (3:6 dihydroxy-4 methoxy-2:5-toluquinone.) According to Oxford, 3) fumigatin was inhibitory toward Staphylococcus aureus and cholera vibrio at 1:30, 000 to 1:50, 000 dilutions respectively, so the antibiotic substance of this mould was about 30 times stronger than fumigatin. Fumigatin melted at 118°C and this substance at 184°C-185°C. Fumigatin could be sublimated in vacuo, while this substance could not be, and in other chemical properties the substance was shown to be definitely different from fumigatin. Oxford3) also studied on the antibacterial activities of several kinds of toluquinone derivatives, and found that 3:6-dihydro-4-methoxy-2:5-toluquinone and 3-hydro-4:6-dimethoxy-2:5-toluquinone, which were synthesized by them, were far more active aginet Staphylococcus aureus than fumigatin. Regarding with antibacterial powers, the substance isolated would be closely resembling to these substances. Raistrick8) said that the morphological and physiological classifica-tion of the moulds was closely paralleled to the biochemical properties of the metabolic products of the moulds. In the former part of this work it was mentioned that this mould was closely related to Penicillium spinulosum which produced spinulosin in its culture media and the identity of the pigment which was produced by this mould with spinulosin confirmed the opinion. On the other hand Raistrick and others18) separated spinulosin from the metabolic solution of Aspergillusfumigatus Fresenius, which on Rhaulin-Thom's media produced fumigatin.17) On the contrary it was a very in-teresting fact that this mould, being closely related to Penicillium spinulosum Thom, produced a substance which showed fumigatin like activities to-ward certain microorganisms.