352 FIRST FORMS OF VEGETATION. 
entophytes sometimes grow with such luxuriance 
that they completely cover the original plants, and 
hide their forms from view ; while at other times 
they are confined to the extremity of the branches, 
or form concentric circles around their base and 
middle. They. consist of simple or branched fila- 
ments, sometimes aggregated into thick radiating 
tufts, like a thick tassel held upwards, each thread 
or filament measuring from the z7g9th to the 
goth of an inch in length, and from the ssdooth 
to the gsipoth of an inch in diameter. Some of 
these seem to be articulated, and to contain spores 
or germs between the joints ; but owing to their 
exceedingly minute size, the power of the micro- 
scope in its present condition is not sufficient to 
resolve them into their component parts, and of 
their processes of growth and propagation we 
know absolutely nothing. Dr. Leidy included all 
those obscure organisms under the confervoid 
alge, and gave them specific names, such as 
Cladophyton, Enterobryus, Arthromitus, under the 
impression that they were independent plants. 
But modern research has proved them to be the 
mycelia or immature forms of various fungi. The 
sarcina is beyond doubt merely an algal condition 
of the common mould, produced and retained 
in that state in the stomach by the special 
food which it meets with there, and which it 
