Excessive salivation in dairy cattle fed certain legume forages is due to infestation of such forages by Rhizoctonia leguminicola. We describe here recent results with an alkaloid from this fungus characterized earlier as its crystalline picrate and Mayer's salt. We now assign structure I to this alkaloid, for which we propose the name slaframine (slafra, to slaver). In vitro experiments show that this compound is not a cholinesterase inhibitor, nor does it stimulate cholinergic fibers directly; rather, it appears to hypersensitize smooth muscle preparations to acetylcholine. Its action can be reversed both in vivo and in vitro by atropine. The synthesis and properties of tetramethylcyclopropanone (1) have been reported. The yield of 1 as prepared by photolysis of 2,2,4,4-tetramethylcyclobutane-1,3-dione was low because of secondary photolyses. Furthermore, 1 is apparently sensitive to oxygen and its handling requires special precautions. We are therefore prompted to report a convenient, high yield synthesis and characterization of 2,2-dimethylcyclopropanone (2), the first example of an unsymmetrically substituted dialkylcyclopropanone.