of Chloroplasts and Leucoplasts . 109 
divided chains of smaller granules. These structures are designated by 
Rudolph as chondriosomes {Mitochondrien, Chondriokonten , Chondriomiten). 
In the mature cells of pith and cortex, he continues, are to be seen side by 
side full-grown chloroplasts and chondriosomes without transitional stages. 
In the elongated cells of the vascular bundle and accompanying tissue, the 
long-drawn-out division stages of chromatophores may deceive one as to 
transitions. It seems more probable that chondriosomes and chromato¬ 
phores (he doubtless means here chloroplasts and leucoplasts), though alike 
morphologically and in staining properties, are structures of a different 
nature without any genetic connexion existing between them. In no case 
are chondriosomes changed into chromatophores. 
From the foregoing summary of Rudolph, it is clear that he recognizes 
two forms of primordia in the meristematic cells of the stem-tip, namely, 
granules and rods. He regards the rods as probable division stages. 
Some of the granules increase rapidly in size, multiply by division, and 
change into leucoplasts and chloroplasts. The long, conspicuous rods, 
some with swollen ends, which are numerous in the elongating cells of the 
vascular bundle, are also regarded by Rudolph as division stages. These 
he calls chondriosomes. He does not show how a leucoplast arises, and 
the small, conspicuous, rounded granules in these cells are referred to in 
his description of Fig. 6 as ‘ Mitochondrien, Chondriokonten und lange 
Chondriomiten ’. 
Sapehin ( 1913 ), using the Mosses Polytrichum , Funaria , Byrum , and 
Mnium as objects of study, distinguishes clearly between plastids and 
chondriosomes, concluding that these two bodies are quite independent 
structures. He strongly supports the doctrine of the individuality of 
plastids. In almost all cells of gametophyte and sporophyte ( 1913 , p. 323 ) 
he finds both chondriosomes and plastids. The former occur as granules 
or delicate, slender rods of varying length. 
In the closing paragraph of this paper, Sapehin makes the astonishing 
statement that in the Characeae, Bryophyta, and Pteridophyta the structures 
known as centrosomes and blepharoplasts are merely plastids. 
Guilliermond has published numerous short papers on chondriosomes, 
in which are presented the results of his observations made upon various 
higher plants and several fungi. He applies the term chondriosome {mito¬ 
chondria , chondrioconte ) to the primordia of leucoplasts and chloroplasts 
and to the bodies of similar form to which he attributes the formation of 
anthocyanin in higher plants, and to the rods and granules in the Yeasts 
and a number of other fungi, which, he asserts, give rise to metachromatin 
granules and fats. In his earlier papers Guilliermond (2, 3, 4) describes the 
formation of leucoplasts and chloroplasts from their chondriosome-like 
primordia. A number of his later papers (8, 10, 13, 14) are devoted to 
the origin of the pigments, anthocyanin, xanthophyll, and carotin of certain 
