537 
Schmankewitsch. In 1871, a dam which divided two 
lakes gave way, so that the water from the higher, which 
was brackish, flowed into the lower, whose water was salt. 
With the brackish water there passed into the lower lake 
numerous individuals of Artemia salina, and there they 
soon settled and propagated. After the dam was repaired, 
the saltness of the lower lake gradually increased until, in 
1874, it had reached its original condition. During this 
period the Artemia salina which had migrated had 
gradually become transformed into Artemia Milhausenii, 
the stages of transformation being actually observed 
one after another. Not content with this observation, 
Schmankewitsch made the matter the subject of direct 
experiment. He— 
“ showed that it was possible to raise a brood of Artemia Milhausenii 
from Artemia salina, which lived in salt water of 4° Beaumé, by 
gradually raising the percentage of salt to 25 0 B. . . . He also 
conducted the converse experiment with perfect success, for he 
brought Artemia Milhausenii back to Artemia salina by breeding 
successive generations in salt water which he made weaker and 
weaker.”—(Semper. The Natural Conditions of Existence as they 
Affect Animal Life. pp. 156-7.) 
We can hardly resist the conclusion at which Semper 
arrives when he expresses his belief that the amount of 
salt is the cause of the transmutation ; and that this is one 
of the cases in which nature exhibits a transforming, as 
distinguished from a selective, influence. 
“ These discoveries are certainly of the greatest interest, for they 
afford a proof we can scarcely doubt, that a change in the amount of 
salt contained in the water can produce a regularly recurring and 
very conspicuous modification of the specific and even of the generic 
characters of certain animals.”—{Ibid. p. 158.) 
The encroachment of the sea would, in course of time, 
bring inland plants into contact with sea breezes and the 
sea itself. How readily the organism of some plants