Claus et al.: "Organized Elements" in Chondrites 583 



processes and are constructed differently (Deflandre, 1936; Timofeev, 1956; 

 Evitt, 1961a, 1962). The spines of real Hystrichospherids grow out from the 

 outer layer of the cell wall through intussusception. These hollow spines help 

 the organisms to float in water (Schiller, 1933-37). Both pollen and Hystri- 

 chosphere spines help to protect the species. On casual observation ragweed 

 pollen grains and certain Hyslricliosp/ieres may look alike (cf. figures 1 and 3, 







10 /u, 



Figures 1 to 5. 1, 2, and 4, pollen grains; 3 and 5, Hyslrichospheres. 



and 4 and 5). Very careful microscopical examination is required by experi- 

 enced microscopists to distinguish the hollow Hystrichospheridmm spines from 

 the solid ragweed pollen spines. This example may emphasize that detailed 

 and careful observations are necessary for the identification of all microscopical 

 plants and parts of plants. 



Fitch and Anders (1963) questioned the validity of using fine morphological 

 criteria in the identification of microorganisms. They claimed that structural 

 features less than 1 /x in size are difficult to observe and they suggested that 

 the resultant identification must be subjective. Yet the science of systematic 



