/ AO \ ("Monthly Microscopical 



\ ^^ J L Journal, Jan. 1, 1B70. 



PEOGEESS OF MICEOSCOPICAL SCIENCE. 



Hie Microsco'pical Structure of Meteorites. — A paper to which we 

 some time since referred, " On the Structure of Meteorites," by Pro- 

 fessor A. Kenngott, of Zui-ich, and which was read in May last before 

 the Vienna Academy, has been reproduced in the ' Philosophical 

 Magazine ' for December, and is accomjianied by a handsome plate, 

 representing the appearance of difierent sections of the Knyahynia 

 meteorite. The structure, says the author, reminds one of the globu- 

 lar diorite of Corsica, and may therefore be supposed to be the result 

 of a process of crystallization within its own substance rather than 

 the aggregation of separately-formed corpuscles. The opaque com- 

 ponents are light-grey' metallic ii'on, greyish-yellow magnetic iron 

 pyrites, and a black substance. These three may best be seen by 

 incident light wlien placed under the microscope. If the light from 

 above is stopped, they all ajipear black by transmitted light. K 

 light from above be admitted, only the black substance appears opaque, 

 the iron appearing dark-grey and translucent, and the jiyrites blackish 

 yellow and faintly diaphanous by the effect of reflected light. In 

 some parts a peculiar network of the transparentmineral substance 

 presents itself. On the whole, the paper gives us the idea that there 

 is in meteorites a field of microscopical research not at all exhausted 

 by the author. 



Tlie Structure of certain Hailstones, though not exactly micro- 

 scopical, is nearly so. It is a paper by M. Abich, illustrated by a plate, 

 in the same number of the 'Philosophical Magazine ' as the above. 



Foraminifera of the genus Trochammina. — Messrs. Eupert Jones 

 Parker and Kirkby continue their papers " On the Nomenclature of the 

 Foraminifera," and in their last paper they give an account — with 

 figures — of the Permian T. ptisilla and its allies. The descriptions are 

 too detailed for abstract. The authors do ample justice to the labours 

 of Professor W. King, whose memoirs on Permian fossils are familiar 

 to geologists. The history of the genus, from the time when it was 

 first noticed twenty years ago, and when it was considered — by all 

 save King, who recognized its relation to Ehizopoda — to be an 

 annelid organism, to the time when its true affinities were established, 

 is clearly stated. — ' Annals of Natui'al History,' December. 



TJie Development of Sorastrum, and on a neio species of Protococcus is 

 the title of a most valuable paper by Mr. Henry" J. Carter, to the Decem- 

 ber number of the ' Annals.' The paper is a long one and deserves 

 the careful attention of those interested in the study of the lower 

 vegetable organisms. The author thus summarizes his observations 

 in the first part of his paper. (1) The development of Sorastrum 

 spinulosum commences by a division of the sporangium into sixteen 

 portions or family groups of eight individuals each. (2) After 

 elimination, these groups increase in size but not in number of in- 

 dividuals, so far as my observation extends. (3) Certain individuals 

 produce one or more family groups, of eight, sixteen, or thirty-two 



