314 Prof. Cay]ey on Equal Roots of a Binary Qua/tic. [Feb. 25, 



V. Note by Professor Gayley on his Memoir " On the Conditions 

 for the Existence of Three Equal Roots, or of Two Pairs of Equal 

 Roots, of a Binary Quartic or Quintic." Received February 20, 

 1869. 



The title is a misnomer ; I have in fact, in regard to the quintic, consi- 

 dered not (as according to the title and introductory paragraph I should 

 have done) the twofold relations belonging to the root-systems 311 and 221 

 respectively, but the threefold relations belonging to the root-systems 41 

 and 32 respectively. The word "quadric," p. 582, line 1, should be read 

 " cubic." The proper title is, " On the Conditions for the Existence of 

 certain Systems of Equal Roots of a Binary Quartic or Quintic." 



iftt, 24. 116* 



