456 A NOTE ON ADSORPTION [ch. 



cytoplasm ; and in this position they often form a somewhat cloudy 

 sphere which constitutes the Nebenkern. In the majority of cases, 

 as in the epithehal cells, they form filamentous structures, and rows 

 of granules, whose main direction is parallel to the axis of the cell ; 

 and which may, in some cases, and in some forms, be conspicuous 

 at the one end, and in some cases at the other end of the cell. But 

 I seldom find the histologists attempting to explain, or to correlate 

 with other phenomena, the tendency of these bodies to lie parallel 

 with the axis, and perpendicular to the extremities- of the cell ; it 

 is merely noted as a peculiarity, or a specific character, of these 

 particular structures. Extraordinarily complicated and diverse 

 functions have been ascribed to them. Engelmann's "Fibrillen- 

 konus," which was almost certainly another aspect of the same 

 phenomenon, was held by him and by cytologists hke Breda and 

 Heidenhain to be an apparatus connected in some unexplained 

 way with the mechanism of ciliary movement. Meves looked upon 

 the chondriosomes as the actual carriers or ti*ansmitters of heredity. 

 Altmann invented a new aphorism, Omne granulum e granulo, as a 

 refinement of Virchow's (or Remak's) omnis cellula e ceUula*; and 

 many other histologists, more or less in accord, accepted the chon- 

 driosomes as important entities, sui generis, intermediate in grade 

 between the cell itself and its ultimate molecular components. The 

 extreme cytologists of the Munich school, Popoif, Goldschmidt and 

 others, following Richard Hertwig, declaring these structures to be 

 identical with "chromidia" (under which name Hertwig ranked all 

 extra-nuclear chromatin), w^ould assign them complex functions in 

 maintaining the balance between nuclear and cytoplasmic material; 

 and the "chromidial hypothesis," as every reader of cytological 

 literature knows, has become a very abstruse and comphcated 

 thing f. With the help of the " binuclearity hypothesis" of 

 Schaudinn and his school, it has given us the chromidial net, the 



♦ Virchow, Arch. f. pathol. Anat. viii, p. 23, 1855; but used, implicitly, by 

 Remak, in his paper Ueber extracellulare Entstehung thierischer Zellen und iiber 

 die Vermehrung derselben durch Theilung, Muller's Archiv, 1852, pp. 47-57. That 

 cells come, and only come, from pre-existing cells seems to have been clearly 

 understood by John Goodoir, in 1846; see his Anatomical Memoirs, ii, pp. 90, 389. 



f Cf. Clifford Dobell, Chromidia and the binuclearity hypotheses; a review and 

 a criticism, Q.J. M.S. liii, pp. 279-326, 1909; A. Prenant, Les Mitochondries et 

 I'Ergastoplasme, Journ. de VAnut. et de la Physiol. Xlvi, pp. 217-285, 1910 (both 

 with copious bibliography). 



