180 THE CANADIAN NATURALIST. [Vol. vii 



the closed tube gives off water. Decomposed by sulphuric acid. 

 The following is the mean of two analyses : 



Silica 43.91 



Alumina 6.47 



Peroxide of Iron 1.23 



Lime 59 



Magnesia 2 7.18 



Water 19.64 



99.02 B. J. H. 



Phosphatic Character of the Shells of Obolus. — 

 Analyses by A. Kupffer show that the shells of Lower Silurian 

 Oholus have nearly the composition of a fluor-apatite. He ob- 

 tained from a specimen from Jamburg in Ehstlands, 



PO5 CO2 Fl FeoOs MgO CaO ign. quartz 



36.57 2.42 3.31 4.90 0.62 50.47 2.57 0.53 = 101.39 



from which, deducting the oxygen in excess, on account of the 

 fluorine, 1.59, leaves 99.80. 



A concretion of Trilobite shells contained, according to the 

 same chemist, PO5 19,45, CaO 45.06, CO2 16.45, Fl 2.88, with 

 a little FeO, MgO, and 6.80 of volatile matters mainly bitumin- 

 ous, corresponding to 42.46 phosphate of lime, 31.81 carbonate, 

 5.91 fluorid of calcium, with some carbonate of iron and other 

 impurities. — Am. Jour. Sc. 



BOTANY AND ZOOLOGY. 



The Fertilization of Grasses. — Prof Hildebrand, a Cer- 

 man botanist who has paid great attention to the subject of the 

 fertilization of flowering plants, has recently made an important 

 series of observations on the fertilization of grasses, and especially 

 of cereals. The agent of fertilization in all grasses, except those 

 few in which the flowers never open, is the wind, insects apparently 

 playing no part in it. With this object the pollen grains are 

 very fine and smooth, so that they are at once dispersed by a 

 breath of air ; the filaments are usually not stiff", but versatile, 

 and the stigma is either feathery, or presents a large surface with 

 numerous indentations in which the pollen is easily lodged. 

 These contrivances render cross-fertilization inevitable; and, 



