ACQUIRED SPECIFIC REACTIONS TO COLOR 175 



tion is precisely the same in the blinded' crab as in those which 

 have eyes. 



Specimen 27, a female, was blinded by cutting off the eye 

 stalks on IX-9-12. Her decoration, which consisted of green 

 and brown algae was carefully stripped off with forceps. The 

 crab was not so restless as Specimens 7 and 26. After the 

 operation the animal remained still with the rostrum toward 

 the side of the aquarium. On IX-10-12, 2 130 P. M., the animal 

 was found to be decorated with poly sip honia and ulva. I 

 observed her at work. She seized a bit of polysiphonia with 

 both claws, tore off a small piece apparently stuffed it into, 

 the "mouth," drew it forth with the right or left chela and 

 placed the weed upon the carapace. If it did not stick the 

 first time she repeated the operation. IX-11-12 the animal was 

 found to be more completely decorated than before with ulva 

 which was placed mainly upon the legs. 



Specimen 28, a large male, was very elaborately dressed in 

 green and brown algae with hydroids, small tunicates, sponges 

 and tube worm on its carapace. After carefully stripping off 

 the decorations with the exception of the tubeworm that could 

 not be removed, the eye stalks were clipped off close to the 

 orbits, IX-9-12. The animal did not appear to be much dis- 

 turbed. IX-10-12, 2:30 P. M., the animal was decorated with 

 two or three large pieces of ulva upon the carapace. It was 

 observed in trying to place a piece of polysiphonia on the cara- 

 pace ; the polysiphonia failed to stick. The animal did not 

 repeat the operation. IX-11-12, placed a non-mutilated female 

 in the aquarium with this male at 3:30 P. M. At 5 P. M. ob- 

 served the two individuals copulating. They remained joined 

 for 30 minutes. Called O's attention to them. 



The conclusion of these experiments is identical with that 

 reached by Bateson 10 and Minkiewicz. 11 Deprivation of the 

 eyes affects in no particular either the series of acts by which 

 the foreign bodies are applied to the animal's body or the ap- 

 pearance of the resulting decoration. 



5. The reaction of blinded crabs to light. — In endeavoring to 

 determine the sort of stimulus and receptor which causes the 



10 Notes on the Senses and Habits of Some Crustacea. Jour. Marine Biological 

 Association. Vol. I, p. 211, 1889. 



11 Loc. Cit., p. 43. Les Crabes Aveugles. 



