42 THE MITOCHONDRIAL CONSTITUENTS OF PROTOPLASM. 



investigators failed to define them accurately and classified granules of totally 

 different nature, under the same heading, with the true mitochondria. 



Chief among them was Flemming (1882, p. 77), who studied granules and fila- 

 ments in cells of many varieties in great detail, and, on the basis of his observations, 

 erected his celebrated "filar" theory of the constitution of protoplasm. We now 

 recognize among his "fila" our mitochondria of to-day, as well as other structures 

 of totally different character. Unfortunately, Flemming's work was limited by the 

 use of a mixture for fixation which contained a relatively large amount of acetic 

 acid, which dissolved the mitochondria in many of the cells which he studied. 



Altmann (1890, p. 100) was able to go considerably further than Flemming 

 by the discovery- of a much superior fixative containing no acetic acid and capable 

 of preserving all the mitochondria. Unhappily, however, his technique was 

 still far from specific and brought to light many granulations other than mito- 

 chondria, like zymogen and fat, which he included with them under the general 

 heading of "Bioblasts." These "Bioblasts" he believed to be ultimate living 

 particles, or elementary organisms, existing in the form of colonies in all cells, 

 and he can not much be blamed for this mistake in view of the very real similarity 

 between mitochondria and bacteria. Nevertheless his theories deterred many 

 from the study of mitochondria. 



F. and R. Zoja (1891, p. 237), following Maggi (1878, p. 326), made an elaborate 

 study of mitochondria under the heading of "Plastiduli fucsinofili" and arrived at 

 the interesting conclusion that they play a part in nutrition which approximates 

 surprisingly closely to our modern ideas. Their results are of special value, inas- 

 much as they paid particular attention to invertebrates, while Altmann confined 

 his observations to the cells of vertebrates. Others, about the same time, de- 

 scribed mitochondria under the headings "Cytomicrosomes," "Neurosomes," 

 "Plasmosomes," " Plasmafaden," and so on (see table 1). 



Another reason for the lack of interest shown in mitochondria during the 

 succeeding ten years is shown by a consideration of the technique. Virchow and 

 his followers in pathological cytology directed their chief attention toward the 

 nucleus; and biologists, dominated by the heredity problem, all looked in the same 

 direction. Consequently their aim in making up fixatives was to show nuclear 

 detail. For this purpose mixtures containing subHmate, alcohol, chloroform, or 

 acetic acid were employed because of their rapid penetration and their action 

 on chromatin. Now, these substances, unless certain precautions are taken, 

 destroy mitochondria; so that the more attention was focussed upon the nucleus, 

 the less chance there was for observation of mitochondria. Thus a vicious cycle 

 was produced and maintained until fixatives made up with a basis of formalin, 

 bichromate, or osmic acid were introduced. 



The newer work on mitochondria may be said to begm with Benda's (1899(/, p. 

 397) study of them in spermatogenesis. He modified Flemming's fluid by reducing 

 the amount of acetic acid in it and devised a staining method by which the mitochon- 

 dria ma}' be colored with crystal violet, which, though not specific, has been of the 

 utmost service to mvestigators. Benda also introduced the term "mitochondria." 



