590 Annals New York Academy of Sciences 



positive Feulgen reaction. These are the plasmalogens (acetal phosphatides), 

 (Schubert, personal communication, N.Y.U.). These latter compounds, how- 

 ever, are not very likely to occur in either the meteorites or in the soils as they 

 are quite unstable and are known to be present only in the central nervous 

 system and in the muscles of animals. Another, as yet unidentified substance 

 yielding a positive Feulgen reaction is the binding material among the cells of 

 some of the species of the green algal genus Oedogonium (Woes-Tschermak, 

 personal communication, Vienna, Austria). This material according to our 

 observations seems to possess a faint pinkish color even in the unstained, 

 living algae, if viewed in the microscope in dimmed oblique light and it may be 

 a compound similar to that described by Palik (1928) in Hydrodictyon (Chloro- 

 phyta) and named as erythropectin because of its pink color. In the case of the 

 Oedogonia the acid hydrolysis seems only to strengthen the pink color already 

 present and in reality we may not be dealing with a positive Feulgen reaction. 

 This question, however, deserves further investigation. 



By using the Feulgen technique on our samples it was found that a con- 

 siderable number of the organized elements of type 1 and type 2, stained 

 homogeneously pink with this stain, whereas the mineral material remained 

 unstained or took a faint greenish color. It was most instructive to see the 

 results of the staining on the different controls; organisms present in the soil 

 or dust samples did not stain, except for their nuclei, which turned red. The 

 mineral and possible organic material in these samples, similarly to the material 

 in the Orgueil and Ivuna meteorites, either remained unstained or took a pale 

 greenish color. The same color developed also in the walls of the pollen grains, 

 whereas their nuclei stained pink (see figure 7, a io e). Pollen grains as a 

 whole never turned pink after the use of this staining method. In 1937, Shuita 

 investigated the nucleic divisions of pollen grains and found the Feulgen stain- 

 ing (by virtue of its complete noninterference with any other cellular element 

 of the grains except their chromatins), was the most suitable stain for such 

 type of studies. 



Another interesting observation was made regarding the starches. Because 

 we could not find any literature data dealing with the effect of Feulgen stain- 

 ing on starch grains it seems to be worthwhile to deal with this problem at 

 some length. Starch (amylum) occurs in the phylogeny of plants compara- 

 tively early. It is present in the green algae and it remains characteristic for 

 the main line of plant evolution up to the Monocotyledoneae. Starch is always 

 an intracellular product and in most of the green algae and in the leaves of 

 higher plants it is formed in the chloroplasts. In the green algae usually a 

 separate organell, the pyrenoid, is in the center of the grains, other grains may, 

 however, directly be deposited in the stroma of the plastids or even in the cyto- 

 plasm (Czurda, 1928). Fritsch writes (1949, p. 67): "The grains . . . appear 

 to grow by apposition of layers on all sides, and their polyhedral form (giving 

 the entire group the shape of a shell) is a result of the fact that free deposition 

 can take place on the external surface." In cases of grains directly develop- 

 ing in the stroma or in the few cases in which they arise in the cytoplasm their 

 shape becomes more or less spherical and the layering takes a concentric shape. 

 Similarly, in any other starch producing plant the grains consist of an inner. 



