THE NEWPORT LABORATORY 157 



with black, yellow, and red pigment cells, which they 

 expand at will, they are able, in about ten minutes, to 

 assume the appearance of the bottom on which they 

 find themselves. From his experiments, Agassiz was in- 

 clined to believe that these fish have the power to dis- 

 tinguish certain colors from others. This question of the 

 development of a sense of color so early in the Verte- 

 brate series leads him to consider the development of 

 this sense in man : — 



" It certainly seems," he writes, " from a physiological 

 point of view, very hazardous to infer, as has been fre- 

 quently done on philological grounds, the gradual devel- 

 opment of the sense of color in early races of mankind, 

 from the color descriptions of Homer and early Greek 

 writers. Certainly, the facility for painting and coloring 

 noticeable in the pottery of the uncivilized races of the 

 world seems unfavorable to this theory." 



Wyville Thomson, writing from the Straits of Magel- 

 lan, had asked Agassiz to come over to Edinburgh in 

 August, 1876, and help him sort the collections of the 

 Challenger, and distribute them to the different special- 

 ists selected to work them up. Agassiz was of course 

 eager to accept the opportunity of studying such an 

 unrivalled collection. This visit was delayed, owing to 

 the illness of his sister, but late in the year, and dur- 

 ing the first weeks of 1877, he spent two months with 

 Thomson at Edinburgh. Of this visit Sir John Murray 

 says : — 



" He would not at that time attend any social func- 

 tions. Every day from early morning till as long as day- 



