594 Annals New York Academy of Sciences 



metachromasia. It would, however, be somewhat premature to conclude from 

 this staining pattern that there are acidic or basic polysaccharides in the acid 

 resistant pellicles of the organized elements. 



One may draw the following conclusions from the staining experiments. 



(1) The specificity of some of these stains is not known. However, it seems 

 unhkely, that 18 of the 19 stains used, gave positive results by chance. To 

 evaluate the meaning of a single staining reaction often seems to be impossible. 

 One cannot argue that a sample is of biogenic origin on the basis of a single 

 staining. However, if a whole array of different stains are applied, which are 

 widely differing in their chemical composition and in their specificity, one can 

 point out biogenic material. 



(2) The use of a great variety of stains (some of them specifically developed 

 for the scanning of certain microorganisms, like Dienes blue-stain for PPLO 

 or the Gridley staining for fungi) facilitated the recognition and, thus, the 

 elimination of earthly contaminants in the meteorite samples. As only small 

 meteorite fragments or powdered material could be used for these studies, the 

 question of contamination could be settled only on the basis of elimination. 

 But by the use of the numerous stains and the relatively great number of con- 

 trols (including soil from the impact area, and dust from the museum) one 

 could recognize and exclude the common contaminants. 



(3) An examination of the soil and dust samples has shown that micro- 

 organisms stained differently from the mineral constituents, i.e., the latter 

 did not stain at all or took a different color. These and the starch and pollen 

 controls have confirmed the specificity of the Feulgen reaction. 



(4) It has been pointed out that not all of the organized elements stained. 

 A gradation in the staining was observed with almost every stain (with the 

 possible exception of safranine). One reasonable explanation for this phenom- 

 enon may be that different degrees of mineralization are present in the or- 

 ganized elements. In terrestrial bitumens microfossils are often differen- 

 tially mineralized (Andreanszky, 1954). 



Physical and Chemical Observations on the Organized Elements 



Fluorescence in ultraviolet light. When preparations of the 4 carbonaceous 

 meteorites were examined with a fluorescent microscope a number of particles 

 became readily visible. Most of these particles fluoresced with a greenish- 

 yellow light when excited by ultraviolet radiation and when Corming 7-59 + 

 Wratten 2B filters were used. A Zeiss fluorescent microscope was applied 

 in these studies. Less frequently, particles fluoresced with a green, pink or 

 red color upon excitation by ultraviolet light. An examination of the thin 

 sections and of the crushed samples has shown that some of the mineral con- 

 stituents (possibly those that were coated with bituminous matter) seem to 

 have fluoresced with a bluish- white color. The fluorescence of the organized 

 elements, in our opinion, can be readily distinguished from the fluorescence of 

 the mineral matter. It is, of course, possible to select the right combination 

 of filters to exclude the bluish-white fluorescence from the yellowish-green or 

 pink fluorescent light. Several of the type 1 organized elements were found to 

 fluoresce with greenish-yellow light, contrary to the argument of Fitch and 

 Anders (1963). Fitch and Anders also claimed that pink colored fluorescence 



