816 General Notes. [ December, 
have, at first, a frothy appearance from the formation of vacuoles, 
but afterwards appear to be filled with protoplasm. They soon 
become flask-shaped, their narrow end touching the periphery of 
the sphere, and the larger end hanging free into the cavity. When 
ready for impregnation they round themselves off into a spherical 
form, and may then be designated oospheres, each being envel- 
oped in a gelatinous membrane or oogonium. The androgonidia, 
or male cells, also contain chlorophyll; they divide but only in 
two directions, thus developing not into a sphere but into a plate 
of cells. They ultimately resolve themselves into a bundle of 
naked primordial cells, each consisting of an elongated body in 
which the chlorophyll has been transformed into a reddish-yellow 
pigment, and of a long colorless beak, to the base of which are 
attached two very long vibratile cilia, and where also is a red 
corpuscle or “ eye-spot.” The whole androgonidium may now 
be regarded as an antheridium enclosed in a gelationous envelope, 
each of the naked protoplasmic bodies being a mobile anthero- 
zoid or spermatozoid. The movements of the vibratile cilia 
eveutually cause the antheridium to break up, the separate anther- 
ozoids setting up a rapid independent motion within the gelatinous 
envelope of the antheridium, which they ultimately break through, 
and then move about rapidly in all directions within the cavity 
of the mother-colony. They assemble in large numbers round 
the odgonia, and some of them finally penetrate through the gelat- 
inous envelope of the latter, and coalesce with their protoplasmic 
contents or odspheres. The fertilized odsphere is now an oospore, 
and develops a new cell-wall, the epispore, which is at first 
smooth, but afterwards covered with conical elevations, giving a 
section of it a stellate appearance. A second perfectly smooth 
membrane, the endospore, is subsequently found within the first. 
The chlorophyll gradually disappears, and is replaced by an 
orange-red pigment dissolved in oil, so that the mature odspore, 
while still enclosed within the mother-colony, is of a light-red 
color, causing the red tinge which Volvox often presents, even to, 
the naked eye, at certain periods of the year. Soon after the 
= odspores reach maturity, the mother-colony breaks up, single 
cells escaping from the combination, and swimming about freely 
in the water; their further history is unknown. The oospores 
fall to the bottom and there hibernate. Their further develop- 
ment has only been observed by Cienkowski, who states that the 
contents of each spore break up into eight spheres which ulti- 
mately break out. 
_ Full details of these interesting processes, with admirable illus- 
trations, will be found in Cohn’s Beitraye zur Biologie der Pflan- 
zen, Vol. i, Heft 3.—A/lfred W. Bennett. 
~ A DOUBLE-FLOWERED CyPRIPEDIUM SPECTABILE.—In describing 
_ this flower it is viewed as it hangs on the stem in its natural position, 
having a right and a left side, the observer facing the open flower. 
