The Simplest For?ns of Life. 151 



matrix uniting the filaments.] Branches tufted, terminal 

 cells hyaline, bristly. Forms lively-green flocks. 

 JD. glomerata, Ag. Stem-cells almost or entirely colorless ; 

 0.033 ^v twice as long, and more or less turgid in the 

 middle. Branches fan-shaped, horizontal. [Ramuli alter- 

 nate.] 

 £>. plumosa^ Ag. Stem-cells like the latter, but larger, as much 

 as 0.04 d ; length = ^ to i d. Branches upright, slightlv 

 expanding, very elongated. [Ramuli opposite.] 

 \D. oppo»ita, Ag., is also described by authors, but it partakes of the 

 characters of both the above species, and is probably not distinct from 

 them. 



D. BiUmgsii, Wood. Frond very gelatinous, filament and primary 

 branches d. ^i^ " very sparsely branched, cells 2-6 times longer than 

 broad, often turgid in the middle. Chlorophyll band bright green, 

 often wanting. Fascicles of branches distant, alternate, opposite, or 

 in whorls of three. Ultimate branchlets terminating in a long, robust, 

 hyaline hair. Resting spores globose, arranged in filaments.] 



III. FAMILY. CONFERVE^. 



Jointed filaments, the cells of which have the property of self- 

 dividing within the lengthening mother cell, so that each generation 

 deposits a new cell-wall within the earlier. 



1. Gen. Microspora^i Th. Jointed filaments, slender, simple, 



not branched, with chlorophyll granules lining the walls. 



All cells produce swarm-spores which are freed by rupture 



of the filament. Forms floating, flocky masses. 

 M. vulgaris, Rbh. Cells about o.oi d. L. = 1.5-3.0 d., bright 



green. 

 JH. floccosa, Th. Cells more slender, slightly contracted at the 



ends. 



2. Gen. Conferva, Link. Slender, unbranched cells, mostly 



w^ith homogeneous contents, forming loose, floating masses, 

 and which perhaps are only sterile forms of the preceding 

 genus. [Species very difficult to determine.] 

 C. tenerrima, Ktz. Cells pale green, smooth, 0.0035 d. L = 2-3 d. 

 Common in springs and ditches. 



3. Gen. Cladophora, Ktz. Filaments branched, robust, cells 



several times longer than broad. Forms floating, intricate, 

 often large masses, swimming free, or attached. [Fila- 

 ments not gelatinous, tufted.] 



