102 Mottier.—Chondriosomes and the Primordia 
the liverworts and other plants studied, being, as stated, lens-shaped with 
a colourless or less densely stained lenticular centre, especially after staining 
with crystal violet. If vacuoles be present in such cells, both classes of 
bodies are mainly aggregated about the nucleus. 
Passing from the apical cell into the root-cap, it is seen that in the 
young cells of the root-cap, namely, the last segment cut off, or the two or 
more cells resulting therefrom, the primordia of leucoplasts are perceptibly 
larger and stain densely. In the third and fourth layers of the root-cap, 
they show a further increase in size, and, in crystal violet preparations, the 
pale or colourless lenticular centre is more pronounced. In the fifth layer 
the typical cell contents are shown in Fig. 14, b. The leucoplasts are 
usually lenticular or elliptical in shape. The almost colourless lenticular 
centre gives the impression that these bodies are hollow or contain an 
inclusion which stains only slightly. The chondriosomes consist mostly of 
small granules or short and more delicate rods. 
In this layer of cells of the root, some of the leucoplasts are seen to 
contain two lenticular inclusions. In the sixth and seventh layers of the 
root-cap in question, all leucoplasts stain poorly with both the haematoxylin 
and the crystal violet. Each contains from one to three or four lenticular 
inclusions, as shown in Fig. 14, a. In the eighth and outermost layer of 
this root, the cells are beginning to separate from each other, and signs 
of disintegration are very apparent. The leucoplasts and their inclusions 
have disappeared from certain cells, but even in these the small granular 
and rod-shaped chondriosomes are very numerous ; they are among the last 
of the protoplasmic contents to disappear from these cells. 
In the cells of the root-cap, as well as in many of those of other parts 
of the root, especially in the cortex, there is present a cluster, or clusters, of 
rounded bodies of varying sizes which do not take the violet or haema¬ 
toxylin stains readily, but which stain a pale orange with the clove oil- 
orange G (Fig. 14, b). As nearly as can be determined, these clusters 
seem to be plastids with partly digested starch inclusions. In many of the 
cells of the cortex and older parts of the plerome cylinder these pale orange- 
coloured clusters are conspicuous, appearing in contrast with the larger 
plastids with their inclusions, which vary in colour from a pale blue to 
a light or smoky grey in preparations rather densely stained with haema¬ 
toxylin. In many cells of the outer cortex, as we pass back into the older 
parts of the root, the pale orange-coloured bodies are the only objects of 
the cytoplasm present in addition to the chondriosomes. The probability 
that they are the products of the plastids is strengthened by the fact that 
they are among the last structures to disappear in disorganizing cells of the 
root-cap and in those of the older parts of the root. 
Passing back from the apical cell to the body of the root, we find, in the 
latest segments cut off, that the primordia of the plastids and chondriosomes 
