ior 
of Chloropiasts and Leucoplasts . 
Since there are always several chondriosomes in spermogenous cells at 
earlier stages in the antheridium, it is extremely doubtful whether the 
blepharoplast, which is preserved in fixing solutions containing acetic acid, 
represents a chondriosome. 
The fear that chondriosomes may be products of disorganized chloro- 
plasts disappears entirely in the case of Anthoceros , since each cell reveals 
its conspicuous chloroplast, in which there appears no sign of dis¬ 
organization. 
It may be worthy of note that the technique, as here employed in 
the study of chondriosomes, is well suited to bring out the structure of 
the chloropiasts, together with their contained collection of rod-shaped or 
granular pyrenoid bodies described by McAllister (1914). The pyrenoid 
bodies, in form and staining reaction, bear some resemblance to the 
chondriosomes which are present in the stalk cells of the antheridia. These 
pyrenoid bodies are, as a rule, larger and stain more densely than chondrio¬ 
somes found in the vegetative cells of the thallus. 
Pallavicinia. In the cells of this liverwort, which contain many 
chloropiasts, chondriosomes are present, especially in the meristematic 
region, although they occur also in the large cells some distance removed 
from the growing point. In form they are similar to those of Marchantia , 
being, however, smaller and less numerous. In the large apical cell, in 
which the relatively small chloropiasts stand out with striking clearness, the 
chondriosomes are few, and in the form of small rods that do not stain 
deeply. As in the apical cell of Anthoceros they are difficult to bring into 
evidence and may readily be overlooked. In the middle of the thallus, 
about four or five cells back of the apex, small round or globular chondrio¬ 
somes were found to be numerous in some preparations. In the older cells 
of the thallus they appear, when stained with crystal violet, as very pale 
blue slender rods or threads. The paucity of chondriosomes in the hair-like 
outgrowths of the growing end of the thallus presents a striking contrast 
to the large numbers found in similar structures in Marchantia. 
Adiantum . In this plant the following statements will be confined to 
the results" obtained in the study of the root-tip, while a discussion of the 
presence and behaviour of chondriosomes and plastids in other organs of 
the fern will be reserved for a future publication. The tips of fresh young 
roots about one centimetre long that had developed directly from the 
growing end of the stem were selected for study. 
In the apical cell there are to be recognized two apparently different 
and distinct primordia: small granules and rods that stain densely and 
uniformly, and larger bodies which are chiefly lenticular in shape. The 
former correspond to chondriosomes, as used in this paper, and the latter 
are clearly the primordia of the leucoplasts (Fig. 13 ). These leucoplast 
primordia present the same form and structure as certain chloropiasts in 
