2 66 Correspondence. [Juty 



issue in his communication worthy of consideration. To those who saw 

 Mr. Lucas's reproduction of the handsome woodcut the P. Z. S. gave me 

 of my drawing of the structure in question, nothing need be said. But 

 to those who have not yet had that pleasure permit me to say a word in 

 my own defence. It will be remembered by those who have read this dis- 

 cussion, that Mr. Lucas claimed that my figure, just referred to is "imper- 

 fect" from the fact that the maxillo-palatincs are broken off. My figure 

 appeared in the P. Z. S. for 1885 (Dec. 1, p. 899, fig F.), and Mr. Lucas's 

 purported copy of it appeared in 'Science' (No. 223, p. 461, fig. 1), some 

 time after my original memoir appeared. 



Now it was my intention, at first, to present here photographic copies of 

 my drawing and Mr. Lucas's copy of it, in order to show, what I am afraid 

 I must say, the unfair manner in which he has acted in the premises in 

 order to support his views. 



But space in 'The Auk' is far too valuable in my estimation to further 

 argue the point, — and I will only say that in the copy (?) which Mr. 

 Lucas made and published of my drawing the backward-turned ends of the 

 maxillo-palatines have been removed, which ends are shown in my origi- 

 nal drawing, small though they be. With this brief remark I close my 

 case, and it will not be resumed by me under any circumstances; no one 

 welcomes honest criticism more heartily than the writer, — but is that hon- 

 est criticism ? 



Speaking now of the individual variation in the skeletons of birds I 

 would like to reproduce here, in illustration of it, a pair of skulls which 

 figured in an article of mine in 'Science' not long ago. As many readers 

 of the 'The Auk,' both at home and abroad, possibly may not subscribe 

 for that estimable journal, I was led to believe that in bringing these draw- 

 ings more directly before ornithologists, many of them could not fail 

 to find something of interest in them. 



These each represent a skull (X 2) of the Yellow-headed Blackbird (A*. 

 xanthocephalus) , the specimens having been collected by myself, and are 

 now in my possession. We are very well aware that throughout animate 

 nature, all specific forms vary more or less, and that the corresponding 

 structures of any two species are never quite alike, either in form or size. 

 So far as birds are concerned, I think it woidd be hard to find a pair of 

 skulls, that would better show, taking this part of their organization into 

 consideration, how great this variation may be sometimes. It is very evi- 

 dent that an exact, description of one of these skulls would not answer for 

 the other, notwithstanding that they are both from birds of the same 

 species, — yet a general description could be written that woidd fully cover 

 all their salient features, and sufficiently differentiate them from descrip- 

 tions of the skulls of other birds. 



With respect to measurements and exact descriptions, however, for any 

 structure, for any particular species of bird, we are in the same quandary 

 in our accounts of such structures among the lower vertebrates as the 

 anthropotomists are with respect to descriptive human anatomy. Much 

 might be written about these two skulls here figured which lack of space 

 forbids, but this will not debar the thoughtful ornithotomist from making 





