PACKAiiD.] TEANSFORMATION OF A.ETEMIA. 509 



that tliere were many bristles. On Eatbke's drawing are 18 such 

 bristles, and even if there had not been more this makes no great dif- 

 ference, especially in view of the fact that the specimens obtained by 

 Kathke, from a salt hike in comparison with ours, could have been more 

 degraded. I must here add that in our Arteynia salina there are some 

 thirty bristles on the terminal lobe of the leg C?) ; in variety a. of Arte- 

 mia salina there are some thirty-three marginal bristles. Had we not 

 had in the Kujalniker Lake in 1874 a second inundation, the genera- 

 tions with the characters of Art. milhausenii would certainly have 

 proved more degraded in relation to this, as there stronger concentrated 

 salt water would have remained in the lake. 



I therefore cannot, without excluding the possibilty of the existence 

 of a self-sustaining species of Artemia milhausenii^ regard the degraded 

 generations of Artemia salina obtained as a species proper, aitd even 

 not then, if such degraded generations exhibited all the characters of 

 Artemia milhausenii: the characters of A. milh. at a certain modifica- 

 tion of the element in the course of several years or also b}^ domestica- 

 tion of several successive generations of Artemia salina in a correspond- 

 ingly changed element. 



After all I hope nobody will think that I endeavor, with the aid of 

 modifying the element in the domestication of animals, to i)rodiice from 

 one species one or more new species. Everywhere I have sought to 

 obtain the intermediate transitional forms between the nearest-allied 

 species, and I approached myself in a moderate degree the characters 

 of the actual species, but we cannot regard such forms as independent 

 ones which have by domestication received characters of unknown con- 

 stancy (in nature), and which we obtain by changing the element during 

 domestication of several generations. It is possible that in earlier times 

 and even also at present in different other localities, as species and an- 

 cestors of our present species such middle transitional forms among 

 the closest allied forms live; nevertheless these forms, resulting from 

 domestication, will neither represent independent species nor varieties, 

 as incipient species, but they only show the tcay in which the characters 

 of a given species combined and which way man, with his zoological ex- 

 perinients, especially with the present means of science, cannot fully 

 follow. Should we succi-ed in i)roducing, with the aid of domestication, 

 a form possessing all the characters of a species existing in a state of 

 nature, then this form will differ from the real in nearly the same way as 

 the best picture will differ from the original. This would be like making 

 concessions to the present conception of si)ecies. Owing to the stated 

 facts it seems to me that our present species can be artificaily pro- 

 duced by man, only this does not happen with the aid of artificial do- 

 mestication, but by adaptation of physico-chemical factors. We should 

 never forget that in nature the characters of a species have a relative 

 stability. 



3. — The characters of the genera Artemia and Branchipus. 



The characteristics of the genera Artemia and Branchipus are demon- 

 strated by many authors, owing to an insufficient knowledge of the 

 characters of the genus Artemia, in a confused and even wrong man- 

 ner. Already in 1853 had Grube made' his protest against the stability 

 of the genus Artemia, seeing that Artemia differs only from Branchi- 

 pus by quasi-negative characters; he also saw the necessity of forming 



1 Grube, Bemerk. iiber die Fhyllopoden in Arch. f. Nat. 185o, pp. 132 to 134. 



