PACKAED.i • TRANSFORMATION OF ARTEMIA. 489 



air) of the salt water. By changing the air-capacitj" of the salt water 

 by a changed concentration of the water, we can at least explain a num- 

 ber of interesting phenomena in the life of Artemia. 



1. If we in certain limits dilute the salt water too much in domesti- 

 cating Artemia, then the animals become, by the too much reduced con- 

 centration of the salt water, transparent, attenuated, their intestinal canal 

 empties and becouies translucent, the gill-sacs often blacken, and the 

 animals will die at the bottom of the jar, as it were, of debility. But if 

 we in time notice at the excessive dilution of the salt water the eickuess 

 of the animals, and if we, instead of augmenting the concentration of 

 the salt water, heighten its temperature a few degrees, the diseased 

 animals will become animated, the intestinal canal fills itself, the mo- 

 tions become more rapid, the animals leave the bottom of the jar, doing 

 well in such diluted salt water at a corresponding higher temperature. 

 It seems to me that such a temperature supplants the superiluous air of the 

 diluted salt water, which in the organism of the animals produced a too 

 great oxidation, leading to weakness, during which the nutritive sub- 

 stances could not replace the consumption. If by too strongly diluting 

 the saltwater the Artemia is consumptive, on account of want of nour- 

 ishment, owing to the dying off of those microscopic organisms on which 

 Artemia lives, these animals would not have revived so soon after a cor- 

 responding increase of temperature. Moreover, microscopic organisms 

 appear in the diluted salt water in great number, even Infusoria, while 

 Joly ^ observed that ArtemiaB are omnivorous, and that they principally 

 live on the lowest organisms of the vegetable kingdom peculiar to the 

 salt lakes, such as various forms of Chlamidomonas, zoospores of Clado- 

 l)hora, &c. 



2. If we, in domesticating Artemia, excessively increase the conceijtra- 

 tion of the ^^alt water and not suflflciently gradually, its alimentary canal 

 becomes solidly constipated, the animals keep nearer the surface of the 

 water and die there, especially during exuviation, which is hereby just 

 as difiScult to overcome as in too much diluted salt water. However, if 

 we in time in this case lower the temperature, instead of diluting the 

 salt water, the animals, even at a too high concentration of the salt 

 water, revive, doing well in such a water with, to a certain degree, low- 

 ered temperature. It seems to me that in this case such a combination 

 of high concentration and temperature is formed, bearing to the equi- 

 librium of aeration in the water, i. e., the quantity of air in the salt water 

 is lessened by the increase of its concentration for just so much, as it is, 

 according to physical laws, heightened by lowering the temperature. A 

 want of nourishment in very saline water is here out of question, since 

 such a water is inhabited by immense numbers of simple organisms, 

 and even at a concentration, allowing self-deposit of salt, great quanti- 

 ties of a red Monad occur, which is known under the name of Monas 

 dunalii Joly {Diselmis dunalii Dujardin= Chlamidomonas dunalii Eaben- 

 horst). 



3. If we gather out of a salt lake the adult Artemise, together with 

 their larvse, and dilute the salt water to excess, then the larvae will soon 

 expire, while the adult individuals long after resist the dilution of the 

 salt water. It appears that the larvae of Artemia die faster in too 

 strongly diluted salt water, because the small stock of material in the 

 organism is not sufficient toward the intense oxydation in consequence 

 of an excess of oxygen in such a water. 



4. In a broad jar and at a low surface of water these animals also 



1 Joly, Sur TArtemia salina. Annales des sciences naturelles, vol. xiii, Zoologie, pp. 

 246 and 255. 



