Ftiidon-Sfrncfurcs in Meieorites. ^ 291 



(2.) Syssideruus. 

 Iron as a continuous, homo- 

 genous mass ; also stony and 

 earthy matter. 

 (3 . ) Sporasidei'oiis. 

 Iron disseminated in grains. 

 Stony and earthy matter 

 predominates. 



{a.) Polysiderous. Con- 

 siderable ii'on. 

 {h.) Oligosiderous. Little 



iron. 

 (c. ) Cry})tosiderous. Iron 

 hardly perceptible. 



In studying meteorites with the microscope, it is a frequent 

 occurrence to find in the sections, formations of a very remark- 

 able nature. 



These sti'uctures exhibiting certain mineral properties, are not 

 crystal-forms, as they lack in most instances totally the straight 

 lines and the angles indicative of pronounced crystalline forma- 

 tion ; but generally show outlines rounded and curved, in many 

 instances presenting, at first sight, a certain similarity to some 

 Avell-known types of organic life. 



The study of these peculiar structures has for some time past 

 claimed my interest and attention, and this paper is to be the 

 record of the work. 



To decide Avhat appellation should be given to these forms, 

 was a matter of considerable difficulty. They are not crystals, 

 yet neither may they be termed amorphous, as they present 

 certain positive I'ecurring shapes. To class them as crystallites 

 might be permissible, for Zirkel's definition, "Crystallites may 

 be termed all those lifeless formations to which a regular xadiate 

 structure {gliederung) or groujjing is peculiar, without their 

 partaking, either as a whole or in their separate parts, of the 

 general properties of cr3"stallized bodies, in particular of a regu- 

 lar polyedral outline,"* is very sweej)ing and extensive, yet in 



* Ferdinand Zirkel : Die Kvystalliten : Bonn, 1875, page 5. 



