Claus el al.: "Organized Elements" in Chondrites 589 



the intensity or shade of the color the organized elements from the minerals. 

 The staining of the soil samples gave similar results. One may make the fol- 

 lowing comments regarding the stains. 



The use of chlor-zinc-iodide in the taxonomy of the OsciUaloriaceae (Cyano- 

 phyta) is mandatory. It is one of the best cellulose reagents and the system- 

 atics of the sheathed genera of the above mentioned family is based upon the 

 positivity or negativity of this reaction, i.e., whether the sheath turns blue or 

 does not stain at all. The 2 other color reactions ascribed to this stain are, 

 however, somewhat less specitic. It is accepted that chitinous substances 

 turn brown, whereas pectic compounds show a yellowish brown coloration. 

 The presence of proteinaceous moiety disturbs this reaction, as proteins will 

 also assume a yellowish brown color. There is, however, some difference be- 

 tween the color given by pectins and that produced by proteins. To differ- 

 entiate between these 2 colors requires either color charts or materials for com- 

 parison. In the case of the organized elements, chlor-zinc-iodide invariably 

 gave a yellowish brown color in the walls, characteristic for pectic substances. 

 Although it would be premature to conclude on the basis of this color reaction 

 that the organized elements possess walls made up by pectins, one is able to 

 rule out the possibility that they are recent pollen or spore contaminants 

 because then they should either become blue (cellulose) or dark brown 

 (chitin) in their walls. Types 1, 2, 3, and 4 have been seen reacting with this 

 stain. 



The blue stain of Dienes was developed for the dyeing of pleuropneumonia- 

 Uke organisms (PPLO) as a substitute for the more complicated Giemsa staining 

 (Dienes, 1939). It is an alcoholic solution of methylene blue and Azure II. 

 Viable PPLO or bacteria will stain deep blue with the stain but will later be- 

 come faint due to decolorization of the methylene blue, whereas dying or dead 

 bacteria stain pink or do not stain at all. Fungus hyphae or spores usually 

 stain very dark blue; cellulose elements, however, stain lilac. This stain was 

 selected not so much to study its effect on the organized elements as to enable 

 us to recognize terrestrial contaminants. However, in the samples under 

 study, no viable bacteria were seen; fungus hyphae were absent and only a 

 single gonotokont was observed. The organized elements turned either bluish 

 or lilac by the stain but the majority did not stain at all. Types 1, 2, and 3 

 have been seen taking up the stain. The mineral matrix in the Orgueil or 

 Ivuna meteorites and in the soil samples turned light bluish. 



One of the most surprising results was obtained with the Feulgen stain. 

 This staining technique was developed for the selective staining of nuclei and 

 chromosomes. It involves the use of the Schiff reagent (leuko-basic-fuchsin) 

 and its reaction with the aldehydes obtained by the acid hydrolysis (HCl) of 

 deoxyribonucleic acids. The staining is considered to be extremely sensitive 

 and very specitic. Since its first description, in 1924, by Feulgen, there has 

 been published voluminous literature dealing with the questions of sensitivity 

 and of specificity of the technique (Pearse, 1960). Several modifications were 

 proposed and, at present, the Feulgen staining has become one of the most 

 reliable and one of the most widely used techniques for the demonstration of 

 DNA in cells, and for the study of nuclear movements during cell division. 

 There are other substances besides DNA that are, however, known to give a 



