EVIDENCES OF EVOLUTION 63 



showed that if the forms without caudal fins 

 were kept in brine which was gradually 

 diluted, a pair of conical prominences, each 

 with a bristle, appeared after some weeks at 

 the end of the tail. Schmankewitsch did not 

 regard the change he observed as a trans- 

 formation of one species into another, and it 

 seems fairly clear that there is no species 

 Artemia milhausenii. What he did show was 

 that alterations in the salinity of the water are, 

 in the course of generations, followed by slight 

 changes in the form of the tail. Bateson 

 and others have shown that there is great 

 variability in the character of the tail and 

 bristles of Artemia salina, and that the tailless 

 form is connected by intermediate stages 

 with the fully tailed typical form. A careful 

 discussion of this frequently misstated case 

 will be found in Bateson's " Materials for 

 the Study of Variation " (1894). 



DIRECT EVIDENCE OF BLOOD RELATION- 

 SHIP. Various workers Friedenthal, Uhlen- 

 huth and Nuttall have brought forward 

 experimental evidence of blood-relationship, 

 and this in the most complete and literal sense. 

 Friedenthal points out that when the blood 

 of a horse is transfused into an ass, that of a 

 hare into a rabbit, or that of an orang into a 

 gibbon, or that of man into a chimpanzee, 



