506 GEOLOGICAL SURVEY OF THE TERRITORIES. 



less, lie iu the disposition of the generations to distribute themselves in 

 much varied elements, that is, to distribute themselves beyond the limits 

 of that element, at which, in the generations, the tj^pical characters of 

 the species preserve, regardless as to the causation of such distribution, 

 by increased augmentation of the individuals, or of such external influ- 

 ences, like moditication of the element in a given locality. Our individ- 

 uals with the characters of A. milhausenii actually represent the degraded 

 and modified generations of A. salina, by the itself rapidly changing ele- 

 ment which also influences the Artemise living in it. Similarly, like cer- 

 tain annual species, which with their generations are much distributed, 

 according to the seasons of the year, represent rather great differences in 

 spring and summer forms. As the most extreme generations of the 

 seasonably distributed species deviate from their species-type toward 

 the nearest allied forms, as is seen, for instance, in Cyclops hrevicaudatus 

 Claus, and Daplmia magna, Leydig, var.,^ so likewise deviates Arte^nia 

 salina with its generations at the most extreme limits of endurable concen- 

 tration of the salt water toward the forms allied to them. But there is 

 a great dilference between these phenomena. Artemia salina changes 

 during the course of several years iu the direction toward A. milliaitsenii, 

 passing through a comparatively large series of generations, and 

 whereby we, iu comi)arison, finally obtain a far greater moditication 

 than any hitherto known deviation in the generations distributed sea- 

 sonally. If there actually exists in nature a self-sustaining species, A. 

 milhansenii, like an A. koeppeniana Fisclier, besides the degraded gen- 

 erations of A. salina and similar forms, then such degraded generations 

 of the highest species of Artemise represent transitory forms toward the 

 lower species of this genus, and indicate the element under whose influ- 

 ence the latter originated. This element must be a salt water of great 

 concentration, together with heightened temperature. It is possible that 

 in long-continued duration of the salt-lake element peculiar to the low- 

 est ArtemiaB, the degraded generations of the higher species of this genus 

 still more degenerate, rendering their characters more permanent, but 

 the forms themselves more independent, even if the principal condition 

 of the origin of independent forms consists in the distribution of genera- 

 tions of these forms producing species in a heterogeneous element, but 

 not (or less) in the moditications of the eleaientof a known district or of 

 a certain water-basin. It seems to me that, with a ver3" gradual increase 

 of the conceuti-atiou of the salt lake, the species populating it will rather 

 die off in this location, than i^roducing a new self, sustaining itself with 

 the element modifying species. 



In view of such jjhenomena a strict scrutiny of such lowest Artemise 

 as A. milhausenii is unconditionally necessary ; all the more, since these 

 species were described by the authors for the greater part from alcoholic 

 specimens, and moi-eover at a time in which the modifying effect of the 

 salt water uj^on the Artemite was yet entirely unknown. 



To solve the question, whether A. milhausenii exists as a self-sus- 

 taining species, I visited during the middle of July, 187G, the Krimea and 

 examined specimens of Artemii© from that salt lake, which is located 

 near the Tatare village Sakki on the way between Eupatoria (Koslov) 

 and Simpherpolis, from which the authors (Fisher von Waldheim, H. 

 Eathke, S, Fischer), who described the Artemia milhausenii obtained 

 their Artemise. I saw that in this lake occurred already at the self-depo- 

 sition of salt specimens fullj^ answering the descriptions of Artemia 



^Consulr my paper in the "Schrifteu" of tlic Neoruss. Soc. of Naturalists. 1875. 

 Vol. iii., Pp. 18 to 44 and 206 to 214. 



