Fusion-Structures in Meteorites. 297 



diameter. To the lower j)art of this, a metal ring has been 

 fastened, which exactly fits into a hole di-illed in tlie fixed stage 

 A, so as to permit the plate B to be completely turned, rotated, 

 resting on A. 



D, 1), are the knobs attached, Avhile E, E, are the steel springs 

 that hold the slide under examination in phice. 



C is graduated to any desired scale ; in this case, it is graded 

 in 45°. 



F is a line engraved on Plate A. 



To- examine a section by polarized light (crossed Nicols), the 

 slide is fastened by the springs E, E ; the line at D is now 

 brought exactly opjoosite to F, and the Nicols set so as to give a 

 dark field. The |)late B is now turned, and whenever a change 

 is shown by the section, a glance at the stage will show through 

 how many degrees it has been turned. 



As C is bored in such a manner that its centre is in the optical 

 axis of the microscope, any object placed exactly in this centre 

 can of course be revolved completely without being thrown out 

 of its position in the field. 



If, now, it be desired to make use of the fixed stage, the 

 whole of B can simply be lifted out of its place, set aside, two 

 steel clamps intended for this purpose fastened into Gr, Gr, and 

 the regular stage is ready for use. 



A short time ago, a statement was made that organic forms, 

 recognized as corals, crinoids and sponges, had been discovered 

 in meteorites. 



Some few savants — among them, it is said, the illustrious 

 Charles Darwin — accepted the evidence proffered in support of 

 this announcement as conclusive ; by far the greater part of 

 scientists, however, brought the full weight of their authority 

 to bear against the assertion, in many instances choosing satire 

 and ridicule as their only mode of attack. 



As the photographs produced of the so-called "organic" 

 structures, and a personal inspection of sections of the identical 

 meteorite {KnyaMnya) from which most of these were taken, 

 convinced me that the structures in question wore analogous, if 

 not identical, with those which I was studying, I felt warranted 

 in giving this view of the question a thorough and impartial con- 

 sideration, before myself advancing a tlieory of their formation. 



