TYPES OF CRYPTOGAMS; THALLOPHYTES 253 
THE STUDY OF NEMALION 
296. Occurrence. — Seven or eight species of Nemalion are known 
in the world, but only one? is widely diffused, being found in Europe 
and on the New England coast from Rhode Island northward. It 
grows in salt water attached to exposed rocks at low-water mark. 
Nemalion represents the largest of the groups of alge, nearly all of 
which live in salt water and have the characteristic color ; but a few 
live in fresh water. 
297. Color.— Fresh specimens or those properly dried for the 
herbarium show the color which is characteristic of the great group 
to which Nemalion belongs. Dried specimens of “Irish moss” 
(Chondrus) and many other species furnish good illustrations. There 
are many variations of shade and intensity. 
Place a piece of a fresh or dried specimen of some species in a 
beaker of fresh water over night or longer and note the color of the 
solution and of the treated specimen. Treat another piece similarly 
with alcohol. A few genera related to Nemalion grow in fresh 
water. What do you infer regarding their color? 
298. Form and General Character.— Examine specimens of 
Nemalion and note the size, shape, mode of branching, nature, or 
consistency of their substance. Examine a fragment of the plant 
with a power of about sixty diameters and note how the structure 
differs from what it appears to be to the naked eye. Do cells appear 
more densely packed or differently colored at any points? 
299. Structure.— From a small portion of the plant cut thin 
longitudinal and transverse sections or pull it to pieces with needles 
so as to expose the inner portion. Place on a slide under a cover- 
glass in a drop of water. With a power of about 250 diameters or 
more examine the general structure of the frond, as shown by a slide 
prepared as above. Note the central portion (axis) of the frond as 
dissected out, consisting of long, slender, thread-like cells. Examine 
and draw the branching rows of cells which, radiating from the 
axis, form the surrounding outer structure of the frond. Note the 
tips of these branches and look for the fruiting organs and fruit 
(spores). 
1 Nemalion multifidum. 
