Temperature Characteristics for Speed of Movement of Thiobacteria.*

The gliding movements of certain Cyanophyceae, Thiobacteriales, and gregarines provide relatively uncomplicated types of comparable activities suitable for quantitative observation. In spite of much discussion, little is known as to the mechanism of this sort of progression. Interpretations have been advanced by a number of writers, t but data required for formulation of a theory of this sort of movement have been lacking. For the present, we are not concerned so much with the mechanics of the movements of Oscillatoria, 23eggiatoa, and other forms creeping in ways apparently similar, but in employing the rate of this type of movement as an index of metabolic changes. For one kind of Oscillatoria it has been shown (Crozier and Federighi, 1924-25) that the rate of translatory movement, in this instance uncomplicated by rotation, obeys the Arrhenius equation for change with temperature. The rates of movement at different temperatures permit evaluation of the constant E, or u, in the equation