BRIEF NOTES ON THE BIRDS OF SAN AMBROSIO AND SAN FELIX ISLANDS, CHILE

San Ambrosio Island, together with San Felix 17 miles to the NNW, and the smaller González Islet form the San Felix Group situated on Lat. 26° 20'S and Long. 80° W. These islands, like all the others scattered off the Chilean coast, are outcrops of volcanic origin which emerge from depths as great as 10,000–14,000 feet below sea level. They lie 500 miles west of the port of Chañaral and about the same distance due north of Juan Fernandez (Robinson Crusoe) Island. As they lack fresh water and lie off the regular navigation routes, civilization has passed them by and, except for occasional visits by lobster fishermen, has left them uninhabited.     

浙江海岛鸟兽地理生态学的初步研究

对浙江洞头岛及舟山五岛的鸟兽调查表明,海岛动物的种数较相邻大陆为低,但种群密度却高于大陆,岛上的某些种类出现生态位扩展的现象。舟山五岛兽类的种数和岛屿面积呈正相关,其关系式为S=2.12A~(0.29),但种群密度随着岛屿面积的增大而下降。文中据此提出了保护和发展岛屿动物资源的某些措施。     

MITOCHONDRIA IN CARDIAC MUSCLE CELLS OF THE CANARY AND SOME OTHER BIRDS

The fine structure of mitochondria from the ventricular myocardium of canaries, sparrows, zebra finches, quail, and geese has been studied. The first three of these birds have very fast heart rates, the quail being intermediate, and the goose has a relatively slow rate. The canary heart has a unique form of mitochondrion containing large, parallel arrays of zigzag or angled cristae. Other cristae, continuous with the zigzag ones and also occupying large parts of the mitochondrial volume, are named retiform because of the hexagonal network which they form, sometimes in a single plane and sometimes three dimensional. These two types of cristae appear to be interconnectible. It is possible that there is a direct functional significance in these peculiar forms, but, in any case, the relative constancy of dimensions in these arrays is probably related to specific properties of the molecules of which the cristal membrane is composed. It is also demonstrated that this membrane is composed in part of approximately 30-A particles which are believed to be protein molecules. This unusual mitochondrial morphology is not seen either in the other fast bird hearts or in the slower ones, so that there is neither a simple correlation with heart rate nor probably with the separate parts of the cardiac cycle. Although none of the other four hearts shows more than an occasional angled crista, there does seem to be a rather gross correlation between heart rate and mitochondrial size and complexity of crista structure, but no correlation with presence or absence of zigzag forms. The cristae of quail heart mitochondria are disposed in unusually large close-packed whorls.     

LAURENCIA MARILZAE SP. NOV. (CERAMIALES,RHODOPHYTA) FROM THE CANARY ISLANDS,SPAIN, BASED ON MORPHOLOGICAL AND MOLECULAR EVIDENCE1

Laurencia marilzae Gil‐Rodríguez, Sentíes et M.T. Fujii sp. nov. is described based on specimens that have been collected from the Canary Islands. This new species is characterized by distinctive yellow–orange as its natural habitat color, a terete thallus, four pericentral cells per vegetative axial segment, presence of secondary pit‐connections between adjacent cortical cells, markedly projecting cortical cells, and also by the presence of corps en cerise (one per cell) present in all cells of the thallus (cortical, medullary, including pericentral and axial cells, and trichoblasts). It also has a procarp‐bearing segment with five pericentral cells and tetrasporangia that are produced from the third and fourth pericentral cells, which are arranged in a parallel manner in relation to fertile branchlets. The phylogenetic position of this taxon was inferred based on chloroplast‐encoded rbcL gene sequence analyses. Within the Laurencia assemblage, L. marilzae formed a distinctive lineage sister to all other Laurencia species analyzed. Previously, a large number of unique diterpenes dactylomelane derivatives were isolated and identified from this taxon. L. marilzae is morphologically, genetically, and chemically distinct from all other related species of the Laurencia complex described.     

THE BIRDS OF THE COCOS-KEELING ISLANDS (INDIAN OCEAN)

The birds of the Cocos-Keeling Islands, in the Indian Ocean, are discussed in the light of specimens and data collected during a stay of eleven months in 1941. Seventeen species were found to be breeding. One of these was an indigenous land bird, four were land birds known to have been introduced, and the remainder were sea birds mostly confined to North Keeling. During this period examples of seventeen species of strays or visitors were taken, of which ten probably occur regularly though in small numbers, while the other seven are true vagrants. Eight of these birds have not so far been recorded from Christmas Island.
Eleven birds listed from the islands by previous visitors were not present in 1941. Two of these were introduced but have failed to maintain themselves, and one, Egrctta garzetta nigripes , seems to be an occasional vagrant. The remaining eight records are all unsatisfactory.