BIOLOGY. 307 



tusks of Eleplias primigenius have, in old individuals, a tendency to 

 curve inward at their extremities. 



Bottom of the Sea. — The precise nature of the mud which is 

 formed at the bottom of the sea has been only recently determined. 

 It consists largely of organic matter, more or less decomposed, 

 interspersed with minute round bodies, about sixteen one-hun- 

 dredths of an inch in diameter. These bodies have been called 

 coccospheres and coccolites, and are so set in the mud as to re- 

 semble mosaic work. Some of these look, under the microscope, 

 like thick watch-glasses. Immense numbers of minute shells are 

 also found. The mud is excessively stick3% being rendered so by 

 minute pellets of a jelly-like consistence. These pellets are dotted 

 all over their surfaces, and are found to contain great numbers of 

 granules, from one four-thousandth to one twent3'-thousandth of 

 an inch in diameter, which are undoubtedly organic in their char- 

 acter, forming one of the representatives of the common ground 

 between plants and animals, about which there has been so much 

 dispute among naturalists. 



Preserving Insects. — Dr. S. P. Knox, of Brownsville, Pa., writes 

 to the " American Naturalist," that, after killing his insect with 

 chloroform, he paints it with a solution of carbolic acid in alcohol 



— 4 grains to the ounce, — and then dries it in the sun. It keeps 

 fresh and beautiful. In stuffing animals, he uses cotton soaked 

 in the same solution. He does not even think it necessary to skin 

 them, as formerly, but simply removes the contents of the thorax 

 and abdomen. 



Velocity of Insects'' Wings during Flight. — According to E. J. 

 Marey, in " Comptes Rendus," the numbers per second are as 

 follows: in common fly, 330; drone, 210; bee, 190; wasp, 110; 

 hawk-moth, 72; dragon-fly, 28; cabbage butterfly, 9. He ol3taius 

 these figures by a very simple and ingenious method, which he 

 fully describes. 



Primordial Flora. — The discovery of eozoon in the Laurentian 

 rocks of Canada was of great interest. One of the most impor- 

 tant discoveries recently made in pala3ontological science is analo- 

 gous with it. It is the detection of what appears to be the remains of 

 a terrestrial flora in certain Swedish rocks of lower Cambrian age, 



— the supposed equivalents of our Longmynd rocks. A peculiar 

 interest attaches to this discovery, inasmuch as it carries back the 

 appearance of terrestrial vegetation upon the earth's surface 

 through a vast interval of time, no land plants having previously 

 been known older than the upper Ludlow beds. The Swedish 

 fossils now discovered appear to be the stems and long parallel- 

 veined leaves of monocotyledonous plants, somewhat allied to tiie 

 grasses and rushes of the present day. These plants apparently 

 grew on the margin of shallow waters, and were buried in sand 

 and silt. Although it is probable that several species, and even 

 genera, may occur in the sand-stoni; blocks which, have been ex- 

 amined, they are provisionally included in a single species, to 

 which the name of Eophi/ton Linnccaum has been given. Eophy- 

 ton, therefore, stiuids \>y the side of eozoon, — the one being, in 

 the present state of our knowledge, the earliest land plant, as the 



