PILL-WORT. 
399 
side. They are simply articulated tubes, or elongated cells 
applied end to end, with frequently a bulbous extremity ; and 
each is produced from one of the cells of the germ.”^ Shortly 
after the appearance of these rootlets the cells of the germ be- 
come flatter and more intimately connected with each other ; 
and at the same time that part of the germ which closes the cavity 
of the sporule becomes hollow, and afterwards points in two 
places. These points gradually lengthen, and on dissection 
each will be found to consist of a closed sheath, one containing 
the first leaf and the other a root : these two apparently distinct 
sheaths communicate with each other, and envelope nearly 
the whole of the germ. The young leaf, when rather longer 
than the sporule, bursts through its sheath, and the root pro^ 
trudes before it is as long as the sporule. ‘‘ After the leaf has 
grown to be many times the length of the sporule, or about two 
lines long, another leaf grows from the germ close to the first, 
to which it is in all respects similar ; and then a bud begins to 
be developed from some indefinite part of the germ, but like the 
leaves and root, from within the sheath, which is now frequently 
much lacerated. This bud is covered by a peculiar kind of 
jointed hairs, whose attachments are lateral, at a short distance 
from their bases, and which contain a few colourless granules. 
This bud sometimes appears after the first leaf, in which case 
there is no second primordial leaf formed ; and is the rudimen- 
tary stem, the first growth from it being a leaf, which exhibits, 
although in a small degree, the first evidence of gyration, and 
shortly after a root, which is furnished with its own sheath. 
^ * The roots are all formed in sheaths, through the apices 
of which they ultimately burst, the sheath continuing to embrace 
the base of the root, whilst a distinct and far more delicate 
sheath closely embraces its point.”f 
The following observations from the same source are well 
worthy the attention of botanists.- — This account of Pilularia 
shows that it is incorrect to say of Acrogens that ‘ germination 
takes place at no fixed point, but on any part of the surface of 
the spores;’ for it is quite certain in this instance that germination 
^ Trans. Linn. Soc. xviii. 485. 
t Id. 487. 
