318 Variegation in I'rinmla sinensis 



In the present connexion, the i-ecunt investigations on chondriosomes 

 in plants, to which reference has already been made, rexjuire some con- 

 sideration, which, however, need only be of the briefest, as the subject 

 has recently been dealt with fully in a general review by Cavers'. The 

 chondriosomes are bodies, the presence of which in the cytoplasm of 

 many organisms has been demonstrated by means of appropriate methods 

 of fixation and staining, 'fhey have been described as persistent cell- 

 organs and are regarded by some writers as homologous with the 

 mitochondria of animal cells, to which Meves and others have attributed 

 important functions in the determination of heritable characters. In 

 another direction, the suggestion has also been made that the plastids 

 of plants are derived from the chondriosomes present in the embryonic 

 cells. At the present time, however, our knowledge of chondriosomes 

 has by no means reached the stage at which any definite conclusions 

 can be drawn as to their sigiuficance. The real nature of the bodies 

 which have been described under this name is still a matter of con- 

 siderable uncertainty'; whether they are persistent cell-organs, and 

 whether the chondriosomes of plants are homologous with those of 

 animals, still remains to be proved, while the suggested relations be- 

 tween the chondriosomes of plants and plastids are very much open to 

 (luestionl Moreover, apart from the uncertainty attaching to the fore- 

 going points, there is, so far as I know, no definite evidence of the 

 transference of chondriosomes from the male generative cell to the egg- 

 cell, in the fertilization of higher plants, even in those cases in which 

 chondriosomes have been described as occurring in the developing 

 gametes of both sexes. 



So far, then, the study of cliDndriosomes has not afforded any results 

 sufficiently well established ti> be adduced either in support of, or in 

 opposition to, the hyf)othesis which has been put forward in explanation 

 of the maternal inheritance of certain forms of \ariegation and chlorosis. 

 It is much to be desired that investigations should be made on variegated 

 plants, by means of the improved methods employed in the stud}- of 

 chondriosomes, with the object of tracing back the ditt'erences between 

 the plastids, which, have been observed in the cells of the young leaf, to 

 the earliest stages in development at which they can be recognized. It 



' '■ Chondriosomes (Mitochondria) and their significance,'" Ncio Phijtolotiist, xiii. pp. 

 'Jfi— 106 and 170—180, 1914. 



- See Cavers, I.e. p. 175, on the resemblance of chondriosomes to myeUn forms. 



■• See, for instance, the recent paper of Scherrer, "Untersuchungen iiber Ban und 

 Vermehrung der Chromatophoren und das Vorkommen von Chondriosomen bei Antho- 

 ceros," Flora, N. F. lxx. pp. 1— 50, 1914. 



