TA ZYQOPHYCER, 
Orver Il. ZYGOPHYCEZ, 
Either unicellular or multicellular Algz, with terminal vege- 
tation, and destitute of true ramification. Cells single, or 
segregate, or geminate, or united in a series. Chlorophyll-mass 
for the most part distributed in plates, or bands, including one 
or more amylaceous granules. 
Multiplication by division of the cells in one direction. 
Propagation by zygospores resulting from the conjugation of 
two cells. 
Consult here Dr. A. De Bary’s “Untersuchungen uber die Familie 
der Conjugaten.” Leipzig, 1858. 
Fairy I. DESMIDIEA. 
Unicellular Algae. Cells for the most part compressed, 
single, or segregate, or geminate, or a larger number united in 
a band, or filament; variable in form, usually constricted in the 
middle, so as to constitute two symmetrical semi-cells. 
This large and interesting family is designedly excluded from the 
present work, as it is proposed to treat them separately. As so many 
students confine themselves exclusively to this family, this proposal 
will doubtless commend itself. The excellent text book by J. Ralfs has 
long been the standard for English students, and would be so still but 
for its scarcity, and the large number of additions in the interval since 
" its publication. 
Famuity II. ZYGNEMACEA. 
Multicellular Alge. Cells cylindrical, equal at both ends; 
fructiferous cells more or less tumid, or inflated, all closely 
conjoined in filamentous families, forming an articulated simple 
thread, with a central cytioblast involved in radiating proto- 
plasm. Cell walls lamellose. 
Chlorophyll-mass effused, or of a definite form, often forming 
a spiral band. 
Vegetation by repeated transverse division. 
Propagation by zygospores, resulting from the conjugation of 
two cells. Conjugation taking place in three ways, lateral, 
scalariform, and genuflexuous. 
This family is sub-divided into three sub-families, according to the 
character of the reproductive process :— 
I. ZyGnemes. 
II. Mesocarres, 
III. GonaTonemEz. 
