CHONDRIOSOMES 85 



division in somatic cells has frequently been reported, and some investi- 

 gators have even held this to be their sole mode of origin — that they 

 arise only from preexisting chondriosomes and are, therefore, permanent 

 cytoplasmic organs. ^° Others have questioned much of the evidence 

 for division and are convinced that, whether or not division occurs, 





.i ^'N ~ Vj, .-^^ 





d e f 



Fig. 44. — Behavior of "chondriosomes" during microsporogenesis in Hdleborus. 

 a, young sporocyte. 6, prophase of first division, c, interkinesis. d, e, cytokinesis after 

 second mitosis. /, young microspore. {After Wagner, 1927a.) 



chondriosomes arise de novo in the cytoplasm. ^^ A third view, namely, 

 that they arise from the nucleus, has not been well substantiated. 



Researches on living material ^^ leave no doubt that chondriosomes 

 may appear anew and disappear, probably with some relation to metabolic 

 processes in the cytoplasm. They are often seen to divide, though the 

 division appears to be passive. In the leaf-cells of Cabomha, Kassmann 

 (1926) saw them rise from the limit of visibiUty, one or two days being 



10 Guilliermond (1912a), Terni (1914), Moreau (1914), Duesberg (1911), Arnold 

 (1912), Friedrichs (1922), Horning (1926). 



" Forenbacher (1911), Orman (1913), Lowschin (1913), Scherrer (1914), Beckwith 

 (1914), Chambers (1915), Lewis and Lewis (1915), Twiss (1919), Meyer (1920), 

 Morelle (1926), Kassmann (1926), Wagner (19276). 



12 Lewis and Lewis (1914, 1915, 1924). 



