THE riltcrLATiHfY APPARATUS <>!' HlliltS. 647 



det irh'-d separately from tin- ei.-tern, out! follows tin- tk'ht side, the other the left side of 



tin- M .rt:i, describing an an-h whose concavity in downward at the base of the heart, on 



th<- liitenil |.;irt-of the truonefl, terminating either very nc.ir oneunothcr, and on the same 



line, ill the junction of tip two jugulars, or on, to tin- riulit. tins other to the left, 



: AO veins, mid not fur from their jinn-lion \ v jth thr axillarics (Fig. 307.) 



" When tin- two raiiids ,-iii>r from tlie stihlnmliar n>>rvoir, they sometimes repeatedly 



A ith each other by .-iiiuons ami curvid branched, as shown in figure 308. 



Ki-. :!"'.'. 



THORACIC DUCT OF SMALL 1UMINAM>. 



" Then all the branches collect in the anterior mediastinum, and constitute a single 

 canal which, mar it> termination, again subdivides into four vessels that open separately, 

 two to the rigl.t and two to the left, in the UMial place. 



" This variety is the most remarkable and complicated of all those observed in the 

 domesticated animals. 



PIG. " The thoracic duct of the Pig, usually single throughout its whole extent. 

 i.- r-omctimes divided, atone to one and a-half inches from its insertion, into two branches 

 which soon reunite in an oval dilatation ; this, after receiving the vessels from the head, 

 neck, and limbs, opens towards the extremity of the left jugular. 



NIVOUA. "In the Dog, Pecquet's reservoir is enormous; in shape it is ovoid, 



and is prolonged between the pillars of the diaphragm into the thoracic cavity. The 



thoracic duct of this animal generally resembles that of the Pig. Yet it sometimes 



ott'rrs in its course nnd termination very numerous variations: Rudbecky has noticed a 



bifurcation above the heart, and another bifurcation whose branches anastomose with 



i -.ich "thrr .-everal times. Swammerdiim and Stenon have figured numerous irregular 



:ii.itj.- d-\ i.-.ons towards the middle of a Mngle canal, to its point of departure. These 



old author* ha\.- imli.-at' d and represented double and triple insertions of different 



forms. I.n.-tly, Hil-ius has shown an arch, or rather u very remarkable ring, at the 



cnirarirr of the conduit, and at its junction with the lymphatic vessels of the neck and 



r limbs, nnd which is more or less analogous to that which I have observed on 



,al occasions in the Horse, Pig, and Cat." 1 



CHAPTER III. 



THK CIRCULATORY APPARATUS OF BT !!!><. 



\Vi will brirtly examine the characteristics of the dill'. -rent portions of the circulatory 



ill.- liraii, b!il-\r"cU, and lymphatic vrs-.-U - of birds. 



ARTICLE I. THE HEART. 



The li. art. in birds, is situated quite at the entrance to the chest, in the median lin^, 

 nnd U < .ntiiinrd in a jrrifanlium that adheres to tin- posterior diaphragmatic sop 1 nn 



1 G. < ',.!;. op. fit. 



