194 ON THE LATE PROF. GARROD's CONTRIBUTIONS 



the Steganopodes, Cypselus and Cypseloides in the Swifts, &c. : in all 

 these cases the first-named genera have but one, the others two, carotids. 

 In other cases, however, the characters of the carotids hold good through 

 very large groups : thus no Passerine bird has ever yet been found with 

 more than a left carotid, and no Pigeon, Duck, or Bird of Prey without 

 two normally placed ones. 



III. The Disposition of the Vessels of the Thigh. 



In Man aud other Mammals, so far as I am aware, the main nerve of 

 the leg is the sciatic ; the main artery and vein are the femoral, running 

 in the front of the leg. In Birds, as a rule, the main artery accompanies 

 the sciatic nerve, running close above and parallel to it ; the vein remains 

 the femoral. 



Ibis, 1881, To these rules certain exceptions were first pointed out by Prof. 

 Garrod. Thus, in Centropus phasianus *, though not in Centropus rufi- 

 pennis, or any of the other Cuculidae examined by him, as well as in all 

 the species of Pipridse and Cotingidae, eight in number, dissected (except 

 Rupicola crocea), the main artery of the leg accompanies the femoral vein : 

 it is a femoral artery t. 



Again, in Dacelo gigantea and D. cervina J, the femoral vein is replaced 

 by one which lies between its normal position and the sciatic artery, 

 crossing over, instead of under, the femoro-caudal muscle ; and the same 

 is the case, as recorded by him in an unpublished (and, unfortunately, 

 unfinished) paper " On the Anatomy of Pelecanoides" in that singular 

 form of Petrel. These two cases are, I believe, the only ones yet recorded 

 of this unexpected arrangement. 



IV. The Mvxcles of the Thigh . 



The myology of birds was always one of Prof. Garrod's favourite sub- 

 jects ; and of his various myological papers, the two enumerated below 

 may fairly be considered the most important, as from the facts detailed 

 therein he drew up, in part, the only detailed scheme of a classification 

 of birds ever published by him. 



In the region of the thigh of birds there are six muscles, which may or 

 may not be present, though no known bird wants them all. These six 



* P. Z. S. 1873, p. 629, note. 



t Since writing the above, I have found the same to be the case in my specimens of 

 Corythaix persa (two), C. porphyreolopha, and C. erythrolopha, and in Musophaga 

 violacea. In Schizorhis africana (two), however, the normal condition persists. 



\ P. Z. S. 1873, p. 629. 



" On certain Muscles of the Thigh in Birds, and on their Value in Classifi- 

 cation. Part I.," P. Z. S. 1873, pp. 626-644 ; " Part II.," P. Z. S. 1874, pp. 111-123, 

 pi. xvii. 



