1878. | Botany. 315 
GENERAL NOTES. 
BOTANY, 
VOLVOX GLOBATOR.—Although this minute organism has long 
been a favorite object for observation under the microscope, its 
rof: F. 
of a highly complicated structure, indicating its proper position 
in a comparatively high-class of Cryptogams, with a marked 
affinity, in some respects, to the Fucaceæ. It must, at all events, 
a be placed in Sachs’ class Odsporez. 
| he Volvox is a minute pale-green globule just visible to the 
naked eye, about one-fiftieth of an inch in diameter, rolling about 
rapidly in clear water, owing to the action of innumerable fine, 
transparent vibratile cilia with which the surface is studded 
These cilia are arranged in pairs, each pair belonging to a sepa- 
rate peripheral corpuscle or cell, each of which contains a green 
protoplasm-body, a minute starch-granule, a reddish brown “ eye- 
pot,” and one or two contractile vacuoles, the cilia being borne 
at the narrow hyaline end. Each is surrounded by a gelatinous 
envelope, which is pierced by a number of canals, all lying nearly 
protoplasmic interior. Since the canals of adjoinin 
respond, the corpuscles appear as if connected together by a net- 
| work of fine reticulations. The outer gelatinous wall of each 
cell is also perforated by two pores, through which the two vibra- 
tile cilia project into the surrounding water. These cells have, 
as far as is known, no reproductive function. Besides these non- 
l reproductive or sterile cells, each Volvox colony includes three 
] kinds of reproductive cells, non-sexual, male and female. The 
non-sexual reproductive cells, or parthenogonidia, are similar in 
4 structure to the sterile cells, but two or three times their size, t.e., 
rom .006 to .0og mm. in diameter. They multiply by repeated 
bipartition, this process having been followed by Cohn until the 
original cell has divided into sixteen. The young colony is sur- 
P 
cavity of the mother colony, each of its cells developing a pair 
of cilia; finally it escapes into the surrounding water. The usual 
number of parthenogonidia which thus develop into infant colo- 
l nies within the mother-colony is eight. The sexual reproductive 
the sexual generation forms the close of a larger or shorter series 
of non-sexual generations. Ihe female cells or gynogonidia 
are at first undistinguishable from the parthenogonidia, but are 
much more numerous, and very early form chlorophyll. They 
