76 ZYGOPHYCER. 
plete the process. The union of the two cells appears to take place in 
several ways. In accordance with one plan, connecting tubes, pushed 
out from near the ends of the cells, grow for a short distance nearly at 
right angles to the long axis of the filaments, and then bend at a right 
angle to themselves, so as to ran parallel to the filament cells. The ends 
of these processes are, of course, opposed to one another, and coming in 
contact, fuse together so as to form a continuous tube for the passage of 
the endochrome. Another method by which neighbouring cells are 
sometimes connected is by the formation of coadjacent pouch-like en- 
largements of the opposing ends, and a subsequent fusion of these 
newly-formed enlargements by the absorption of the end wall between 
them.” 
“There is still another method of conjugation, the so-called genufleau- 
ous, in which, instead of a connecting tube being formed as the medium 
of union, two cells of opposing filaments become sharply bent back- 
wards, so that their central portions are strongly thrust forward as 
obtuse points, which, coming in contact, adhere, and allow of a passage- 
way between the cells being made by the absorption of their cohering 
walls.”— Wood's F. Water Alge, p. 161. 
Hassall says that the conjugation in Zygnemacee results in the pro- 
duction of “ adark body, of either an oval or circular form, and en- 
veloped in membrane, which Vaucher, Decaisne, and Jenner regard as 
the true spores, but which Agardh declares resolve themselves after a 
time into zoospores, an opinion in which I concur, applying the term 
sporangia to them.” It need scarcely be added that this view is erro- 
neous, the resulting body Seneaiane direct after a period of rest, and 
termed a zygospore. 
The same author makes also sities statement, rather vaguely stated, 
which is not confirmed by experience. “It is curious to remark that 
the cells in one part of the same tilament will part with their contents 
and remain empty, while in another they will be the recipients of the 
contents of the cells of another filament.” His remarks on agame@- 
sporous Conjugate will be illustrated under the sub-family Gonatonemee. 
Sub-Family 1. Zyenemen. 
Cells cylindrical, united in threads. Zygospore undivided, 
and mostly contracted, passing into the resting condition, after- 
wards developing into a germ-cell, divided into a basal cell, and 
a thread-cell, capable of division. 
As hereafter explained, this sub-family differs from the Mesocarpee 
chiefly in the development of the spore, which is not surrounded, or 
accompanied, by two to four deciduons lateral cells. 
Genus 44. ZYGNEMA. Kutz. (1843.) 
Cells with two axile many-rayed chlorophyll bodies standing 
near the central cell nucleus, each containing a starch-granule, 
or quite filled with dense granular contents, surrounding two 
starch-granules lying near the centre, (a) zygospore in the 
bladdery middle space between the ladder-like united pairing 
cells (6), copulation ladder-like, or lateral between two cells 
of the same thread. 
