the water of our salt-marshes before St.-Hilaire and Turpin. As I was at that time employed in teaching Natural History in the Royal College of Montpellier, where I had among my pupils several youths who have since become distinguished masters themselves (Louis Figuier, Amédée Courty, and Henri Marès, for instance), I too had a desire to study the curious phenomenon of the reddening of water, and to this end I visited the salt-works of Villeneuve, two or three miles distant from Montpellier. The water there was then of a very decided red color. I collected on the spot some samples of the water which looked most like blood, and also of water which, being less briny than this, was also of a fainter red color. Under the microscope the water collected in the various compartments exhibited myriads of minute creatures, with oval or oblong bodies, often compressed in the middle, but sometimes cylindrical. Very young individuals were colorless, those a little older were greenish, and the adult were of a deep red. The mouth had the form of a conical prolongation, and was retractile; they were eyeless, and the stomach and anus could not be clearly made out.
|Fig. 5.||Fig. 6.|
|Dead Monads, colorless.||Part of the Digestive Tube of Artemia Salina, in which are seen (a, a) dead hut not digested monads, and (b, b) cubical salt-crystals.|
With a high-power microscope I was able to see in the anterior part of these supposed protococci two long, flagelliform, and perfectly transparent processes which they kept in rapid motion, and by means of which they swam about in the drop of liquid spread out on the slide of my instrument. There was no longer room for doubt. The protococci and hœmatococci of Messrs. Dunal, St.-Hilaire, and Turpin, were animals—true monads, and I gave them the name of Monas Dunalii, in honor of my preceptor, Prof. Dunal. He was the first to suspect the true cause of the red color of the Mediterranean salt-marshes; but he had only an indistinct insight into the matter. He examined the