142 MR. F. E. BEDDARD ON THE [Mar. 18, 



3. Notes on the Auatomy of the Condor. By Frank E. 

 Beddakd, M.A., Prosector to the Society. 



[Received March 4, 1890.] 



Ill tbe present communication I wish to direct attention to the 

 structure of the trachea and of the heart in the Condor. Certain 

 interesting statements by Prof. Gegenbaur ' concerning the structure 

 of the right auriculo-ventricular valve made me specially anxious to 

 study this bird, which the death of a specimen at the end of last 

 year has enabled me to do. 



In the trachea I refer to one or two structural points of slighter 

 importance. 



1. Heart. 



The general structure of the right auriculo-ventricular valve in the 

 Bird's heart is well known : there are, however, some discrepancies 

 among the descriptions of the corresponding valve in the ('rocodile, 

 with which it is universally agreed that that of Birds must be com- 

 pared. 



Gegenbaur's description of this valve in tbe Crocodile is very de- 

 tailed, though unaccompanied by figures. The valve consists of two 

 halves, a muscular and a membranous ; the former borders the an- 

 terior and outer margin of the atrio-ventricular orifice, the latter the 

 septal margin of the same. " The hinder lateral part of the ventri- 

 cular cavity apj)ears spongy from tbe presence of a number of fleshy 

 trabeculae : of tliese one is of importance, which runs from the anterior 

 ventricular wall upwards and backwards to the jutting-out muscular 

 valve to be inserted in the neighbourhood of its free margin. This 

 muscular trabecula is not in any way distinguished from the neighbour- 

 ing ones ; it is, indeed, less conspicuous, but it is constant (so far as the 

 small number of hearts examined [4] enable me to say). It is more 

 conspicuous in the Crocodile than in the Alligator, and is readily seen. 

 It forms a fleshy bridge from the muscular margin of the ostium to 

 the lateral ventricular wall." 



In comparing these arrangemeuts with that which characterizes 

 the Bird's heart. Professor Gegenbaur duly calls attention (p. 3S0) 

 to the absence in the latter group of all traces of the membran- 

 ous valve except in the Condor, which is described as follows : — 



" Only in the heart of Sa7-corhani2}hus do I find a peculiarity which 

 has interest in this connection. From the anterior origin of the 

 muscular valve on the septutn venfriculo7-um a. fold runs backwards, 

 which is formed by a thickening of the endocardium. The fold 

 runs obliquely backwards and downwards and crosses in its direction 

 the margin of the muscular valve. The course of this fold corre- 

 sponds to the line of origin of the membranous valvular flap of the 

 Crocodile ; I think it reasonable therefore to regard it as a remnant 

 of the structure which is further developed in the Crocodile." 



' " Zur vergleichenden Anatomie des Herzeus," Jen. Zeiticli. Bd. ii. (1866), 

 p. 365. 



