Claus et al.: "Organized Elements" in Chondrites 585 



genie compounds, such as certain hydrocarbons, cytosine and purines, should 

 have already provided an answer to their last postulated requirement. 



The Applicahilily of Biological Stains to the Investigation 

 of Meteorite Samples 



The use of biological stains for demonstrating cellular structures is indispen- 

 sable in microscopical biology. During the preceding 2 decades a better under- 

 standing of the chemical nature of dyes and the chemical reactions involved, 

 has made it possible to use the color developed as a specific indicator for the 

 presence of a certain compound. With the development of color indices and 

 standardization of the marketed dyes (Conn, 1953) many of the unpredictable 

 results or uncertainties originating from the varied staining procedures have 

 been eliminated. At present there are still some major gaps in the knowledge 

 of the reaction mechanisms of several dyes and their exact specificity in several 

 cases is not known; however, one is able to use them with a certain degree of 

 confidence if one fulfills the following three criteria. (1) Use a whole array 

 of structurally different dyes on the same substrate. (2) Use adequate amounts 

 of controls. (3) Rely more on stains which chemically react with the sub- 

 strate (or before application are in colorless form) than on those which are 

 merely adsorptive in nature. 



SUdes were prepared essentially in 2 ways. (1) The sample was either 

 crushed or dispersed on the slide in double distilled water, was covered, and 

 the aqueous staining solution was, during the period of observation, constantly 

 sucked through the preparation. (2) The meteorite and soil samples were 

 crushed between 2 slides the surfaces of which were coated with fresh egg 

 albumin. The other materials like pollen or starch grains, etc. were dusted 

 over the albumin covered slides with a fine brush. The slides prepared in this 

 way were then subjected to the staining procedures, washed with tridistilled 

 water, dehydrated, mounted in balsam and coverslipped. In cases of the 

 eosin and hemato.xylin-eosin staining instead of eggwhite, collodium was used 

 for adhesion. The staining with ninhydrin was performed in small test tubes, 

 and the material was transferred to glycerin and examined in it. During the 

 staining procedures special care was taken not to contaminate or crosscontami- 

 nate the preparations, therefore the stains were freshly made up with tri- 

 distilled water and the different specimens were stained in separate sets of 

 copUn jars. 



As can be seen from table 1, 19 widely differing biological stains were used, 

 of which only 1, i.e., safranin, is considered to be a true adsorptive stain (the 

 nature of dyeing with the eosin stains, like Azure II, and Dienes PPLO blue 

 stain is still debated). Of the 19 stains only 1, Sudan IV, gave negative re- 

 sults with the organized elements. All of the other stains were found to be 

 positive. One has to emphasize, however, that only a portion of the organized 

 elements stained with the different stains and the proportion of the stained to 

 the unstained particles varied from stain to stain. One has also to admit that 

 several of the dyes used stained not only the organized elements but also a 

 portion of the mineral material. However, one could easily distinguish by 



