90 INTRODUCTION TO CYTOLOGY 



clover nodule show distinct differences in fixing and staining reactions. 

 Similar results are obtained by Milovidov, using another method on 

 lupine nodules. Horning reports that chondriosomes, but not bacteria, 

 are stained with a new vital dye derived from Janus green. Bowen 

 cites as further evidence against the bacterial interpretation the remark- 

 able behavior of the nebenkern (chondriosomal material) in the animal 

 spermatid. Wallin attributes the peculiar properties of chondriosomes 

 to their long symbiotic history and is inclined to interpret the nebenkern 

 as a stage in the bacterial cycle somewhat analogous to the " symplasm " 

 in other bacterial forms (Lohnis). He reports further that experiments 

 appear to indicate that chondriosomes can be cultivated independently 

 on nutrient agar. The final evaluation of this evidence is awaited with 

 the greatest interest. 



Chondriosomes and Plastids. — The general theory of Meves that 

 many intracellular differentiations are due to transformations of chon- 

 driosomes included the proposition that the plastids of plant, cells arise 

 from these bodies. This view has been expressed in one form or another 

 by a large number of workers." In Asparagus and Pisum, for example, 

 Lewitsky concluded that chondriosomes become leucoplasts in the root 

 and chloroplasts in the stem and leaf. Other investigators^^ have main- 

 tained that plastids are surely or in all probability quite distinct from 

 all other elements in the cell and that confusion has arisen because differ- 

 ent kinds of minute bodies are so similar in appearance. No problem 

 in the cytology of recent years has been more perplexing than this one.^^ 



That some distinction must be made between the small bodies which 

 develop into plastids and those which do not has become increasingly 

 evident. Guilliermond, whose extensive studies^" are particularly note- 

 worthy, came to recognize such a distinction, but he considered both 

 types as chondriosomes essentially equivalent to those of animals: the 

 "active" ones are elaborative elements developing into plastids, while 

 the relatively "inactive" ones remain small and perform undetermined 



27 Lewitsky (1910, 1925), Forenbacher (1911), Guilliermond (19116 et seq.), Cavers 

 (1914), Moreau (1914), Nassonow (1918), Emberger (1920, 1927), Alvarado (1923), 

 Friedrichs (1922), Bouygues (1924), Mangenot (1925), Kirby (1928), Cowdry (19266), 

 Senjaninova (19276c), Motte (1928), Cunha (1929), Zirkle (1929c), Loui (1930), and 

 others. 



28 Meyor (1911), P. A. and P. Dangeard (1919 el seq.), Limdegardh (1910), Rudolph 

 (1912), Mottier (1918, 1921), Scherrer (1914), Noaek (1921), Harper (1919), Lowschin 

 (1913, 1914), Sapehin (1915), Krupko (1926), Bowen (1927a6, 1929a), Bowen and 

 Buck (1930). Kassmann (1926) expresses uncertainty. 



29 See the discussions by Bowen (1929a) and P. A. Dangeard (1931). The indis- 

 criminate use of the terms "chondriosomes" and "mitochondria" for small bodies of 

 many kinds must be borne in mind when reading the literature in this field. 



^ A classified list of Guilliermond's researches up to 1921 is given by himself 

 (1921z), together with a list of works by his associates. See also Guilliermond, 

 Mangenot, and Plantefol (1933). 



