PACKARD. ] TRANSFORMATION OF ARTEMIA. 509 
that there were many bristles. On Rathke’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 
Rathke, from a salt lake in comparison with ours, could have been more 
degraded. I must here add that in our Artemia salina there are some 
thirty bristles on the terminal lobe of the leg (2); 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 milhausenti, regard the degraded 
generations of Artemia salina obtained as a species proper, aud even 
not then, if such degraded generations exhibited all the characters of 
Artemia milhausenii: the characters of A. miih. at a certain modifica- 
tion of the element in the course of several years or also by 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 preduce 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 way in which the characters 
of a given species combined and which way man, with his zoological ex- 
periments, especially with the present means of science, cannot fully 
follow. Should we succeed in producing, 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 realin nearly the same way as 
the best picture will differ from the original. This would be like making 
concessions to the present conception of species. Owing to the stated 
facts it seems to me that our present species can be artifically pro- 
duced by man, only this does not happen with the aid of artificial do- 
mestication, but by adaptation of physico-chemical factors. We shoul 
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 
1Grube, Bemerk. iiber die Phyllopoden in Arch. f. Nat. 1853, pp. 132 to 134. 
