Holospora spp. and "Candidatus Gortzia infectiva", known as Holospora-like bacteria (HLB), are commonly found as nuclear endosymbionts of ciliates, especially the Paramecium genus. HLB are related by phylogenetic relationships, morphological features, and life-cycles, which involve two alternating morphotypes: reproductive and infectious forms (RF, IF). In this paper we describe a novel species...

Truncated hemoglobins (trHbs), are a distinct and newly characterized class of small myoglobin-like proteins that are widely distributed in bacteria, unicellular eukaryotes, and higher plants. Notable and distinctive features associated with trHbs include a hydrogen-bonding network within the distal heme pocket and a long apolar tunnel linking the external solvent to the distal heme pocket. The...

Some media are described which inhibit bacterial growth, but are favorable to protozoan development. A purification technique, which takes advantage of geotropic responses, was devised and used successfully with 7 species of protozoa, including flagellates and ciliates. The method was also used with a Spirillum. For one flagellate which could not be purified in this manner, a procedure involvin...

Information transfer is a fundamental of life. A few studies have reported that cells use photons (from an endogenous source) as information carriers. This study finds that cells can have an influence on other cells even when separated with a glass barrier, thereby disabling molecule diffusion through the cell-containing medium. As there is still very little known about the potential of photons...

N TYPICAL biotypes of the Johns Hopkins stock R of P. aurelia, I SONNEBORN (1936) has shown that, when surplus animals from isolation lines are collected in a small mass culture and placed a t 31OC, conjugation invariably occurs if the animals have recently been through a nuclear reorganization (that is, endomixis or conjugation), but never a t other times. In the present paper we contrast the ...

The Mechanism of Enzyme Actions: DR. K. GEORGE FALK .................................. 471 Obituary: Michael Idvorsky Pupin: PROFESSOR A. P. WILLS 475 Scientific Events: Annual Meeting of the Trustees of Science Service; Annual Meeting of the American Academy of Arts and Sciences; Betirement of the Secretary of the Zoological Society of London; Award of the Daniel Guggenheim Medal for Aeronauti...