THE HATCHINGS OF ROTIFERS IN VOLVOX GLOBATOR. 165 
cannot be kept alive for more than five or six days, and this fact 
prevents continuous observation for any lengthened time; hence 
it happens these specks often pass away unobserved, and their 
actual nature, for the most part, is undiscovered and unexplained. 
Early in March the writer collected a quantity of Volvox, and at 
once noticed the white specks, usually of a round or oval shape ; 
being fortunate enough in keeping it alive for eleven days, he was 
enabled to watch the whole hatching process. 
Ehrenberg divides the family of the Notommata into 23 species; 
two of them are parasitic,— lV. petromyzon and LV. parasitica. He 
remarks that “the latter class lives in the globes of the Volvox 
globator, where it deposits its eggs, which are there hatched ; and 
when of a proper age, the creature eats its way through the hollow 
sphere.” 
From this quotation it might be inferred that the presence of 
eggs in Volvox is not an accidental occurrence, but rather a natural 
and usual circumstance. 
These creatures are also found in other Alge, a7z., the Vaucheria 
clavata, as well as in the cells of the Bog Moss. They have a 
roaming disposition, and are of no settled habitat ; their fecundity 
is enormous, and their power to endure the widest extremes of 
temperature remarkable. 
More frequently, the eggs are found in decaying Volvox, having 
rents and openings all round; and this condition of the plant 
favours the view that the eggs have been accidentally washed 
in; but the writer has seen them in perfectly sound and healthy 
Volvox, without any breach, so far as could be seen, in the peri- 
pheral envelope, and, indeed, he has seen them in the interior of 
young Volvox whilst yet within the parent sphere. 
On the fifth day of observation, the stirring of life in the egg was 
noticed ; and in two or three days more the whole hatching process 
was completed. 
The Rotifer, after living on whatever nutriment there was in the 
egg, commenced crawling about in worm-like fashion, on the inner 
surface of the globe ; the Volvox, all the time, continuing the usual 
spinning and rolling motion. Whether the activity and freedom of 
of the plant is essential to the life of the Rotifer or not, it will be 
noticed that when the Volvox dies—which is usually very sudden 
—all observation is terminated, for the house and its tenants are 
together dissolved and disappear. 
On compressing a newly hatched Rotifer chlorophyll grains are 
found in the stomach, and this may indicate the instinct of the 
parent in placing her eggs where congenial food was at hand; but 
how the creature “deposits its eggs within the globes of Volvox 
globator” is a question which requires answering, and is worthy 
of the attention of all microscopic naturalists. The hatching is 
best witnessed with a dark ground illumination. 
