Page:Popular Science Monthly Volume 4.djvu/218

206 animalcules only after they were dead, that is, at the moment when they had become globular and motionless, like protococci; and his specimens were dead, because he had filled his vials up to the brim with the water, and then sealed them hermetically. But these little animals must, above all things, have free respiration. Accumulated in immense numbers in a very small quantity of water, with the outer air entirely excluded, they all died while being carried from Villeneuve to Montpellier. They were then taken for protococci, being motionless and globular. I took precautions against committing this mistake, by only half filling my specimen-tubes, and, better still, by examining the water of the salines on the spot.

 (adult) natural size, and highly magnified. o. Median eye. y, y. Pedunculate eyes. a, e. Antennæ, p. Incubatory pouch with eggs. ab. Abdomen, ap. Tail-shaped appendages. c. Digestive tube.

It is a remarkable fact in the history of the Monas Dunalii that, like the Protococcus nivalis, which gives to the snow of the polar regions now a green tinge, anon a red, this animalcule presents, when young, a green tinge, which changes later to brick-red, and then to blood-red.