Year Book, Issue 21

absolute magnitude acid activity amebas Amer amount amylase apparatus appear atoms cells cent changes chemical chromosomes clasmatocytes complete continued cooperation crystal curves Department of Terrestrial determined diatom diploids distribution earth-current Earth's effect electric expedition experimental experiments factors field fumaroles galvanometer given growth important increase indicate instruments intensity interferometer investigation Jour Laboratory leucite light lines luciferase luciferin magma magnitude material measurements melilite ment metabolism meters method mirror motion Mount Wilson mutant Naachtun nebulæ normal observations Observatory obtained ocean parallaxes period photographic photosynthesis plants polar possible pressure produced Professor radial velocities radiation reaction records reef region relation slope sodium solar solution species spectra spectral type spectrograph spectroscopic spectrum stars stations Stela stellar sucrose sugar sun-spot surface telescope temperature Terrestrial Magnetism tests tetraploids tion Tortugas Uaxactun variation various velocity Washington Watheroo wave-length