THE BESPIBATOBY APPARATUS IN BIRDS. 481 



Palmipeds. At other times it inclines backwards, and the anterior reservoir is larger ; 

 this arrangement is peculiar to the Gallinacse. And, lastly, this parlition divides the 

 intercepted space between the diaphragms into two equal cavities ; rapacious birds offer 

 numerous examples of this. 



"Behind, these reservoirs stand against the abilominal sacs, from which they are 

 separated by the thoraco-abdominal diaphragm ; below, they respond to the sternal ribs 

 and the lateral parts of the sternum; above, to the pulmonary diaphragm; inwards, 

 to the thoraoo-abdominal diaphragm ; outwards, to the veitebrul ribs and intercostal 

 muscles. 



" A parabolic opening, situated in the middle part of the external border of the lung, 

 or a little more behind, establishes their communication with that orgim This orifice, 

 which is remarkable for its great dimensions, occupies the extremity of a voluminous 

 bronchial tube which follows the direction of the generating trunk, and in such a manner 

 that this trunk appears to pass directly towards the posterior diapliragmatic reservoir, 

 and to open as a canal." 



5. Abdominal reservoirs (Fig. 246, 5). — " The two air-sacs situated in the abdiimen 

 present themselves, when inflated, as two enormous bladders, the capacity of each 

 differing Ibut little from the volume of the trunk. Situated between the superior 

 and lateral parietes of the abdomen on one side, and the abdoininul viscera on tue 

 other, tliey cannot be dilated without driving the intestinal mass downwards and 

 inwards. 



" Their anterior extremity, continuous with the lung, is somewhat inflected to pass 

 under the fibrous arch extending from the spine to the pelvis. 



" Their posterior extremity, dilated and volmninous. responds to the cloaca. Out- 

 wardly, they adhere by cellular tissue to the thoraco-abdominal diaphragm, the parietes 

 of the 'abdomen, and those of the pelvis. Inwardly, they are in contact with the intes- 

 tinal mass and the testicles or ovaries. Below and in front, they rest on a fibrous 

 septum, which in all birds divides the abdomind cavity into two smaller cavities: one 

 anterior, which represents the abdomen and lodges the liver, the other poateriur, which 

 represents the pelvis and contains the stomach and intestines. This fibrous septum is ex- 

 tremely remarkable in large birds, particularly the Ostrich, in which it has been described, 

 by Perrault as a transverse diaphragm ; it is insertea into the entire circumference of the 

 pelvic bones and sustains the stomach as well as the intestinal tube. Below and 

 behind, the abdominal reservoirs lie on the intestines. Above, these sacs cover the, 

 inferior face of the kidneys, and there furnisli three prolongations : 1, A suprarenal 

 prolongation ; 2, Two femoral prolongations. . , a . , ■, 



" The suprarenal prolongation leaves the principal reservoir at the postero-exlernal 

 part of the kidneys ; from thence it passes obliquely upwards and forwards, to spread 

 over the superior surface of the kidney, wl.ich it depresses when the abdominal sac is 

 infiated. Arrived at the internal border of the kidneys, these prolongations are intro- 

 duced between the transverse processes of the sacral vertebra), and ascend from behind 

 forwards to the height of the two first dorsal vertebrae, forming two triangular canals 

 situated above the sacrum, in the sacral channels, and separated fioin one another by a 

 series of corresponding spinous processes. The suprarenal prolongations are not 

 present in all birds; they are particularly observed m the Gallmacie and diuinal 

 rapacious birds. In some Palmipeds, the Swan for example, they are equally developed ; 

 in the Ostrich, they are replaced by the supraspinal canals. „ „j „ „„<,t»rinr 



"The femoral prolongations are two in number--an anterior small and a posterior 

 large- they arise from the abdominal reservoir at the cotyloid cavities, and leave the 

 pXs in traversing the bony opening through which the crural vessels pass ; after clear- 

 FnTthe limits of these cavities, they spread around the coxo-femoral articulation, and 

 tefminste Tn a caecum in the majority of birds. I., diurnal birds of prey they commu- 

 Sewfth the femoral canal by' -'orifice situated at the anterior part of tli^^^^^^^^^^ 

 trochanter These prolongations, very developed m the 0»trich, also open m it into tne 

 femorTcI;ity it is not without surprise that we see this airangement, which ispecuhar 

 toTirds remarkable foi their rapidity and power of flight, also present m those to which 

 LaHocrotThas been entirely de\ied The a^domin^l ^servous com^^^^^^^^^ 

 . the lung by an orifice situated beneath the fibrous arch of the diaphiagm, and aisposea 



like the rose of a watering-can." t5„ ™„ n rriio /.rimTnuTuVaHnnq of the 



CoMMDNiOATiON OP THE Eesehvoiks WITH THE BoNES.— " The communications ot tne 



respiratory apparatus with the skeleton in birds are extremely numerous. W. wiU 



successively examine those belonging to each reservoir. 

 "ThebLeswhi.hreceivearfr^^^^^^^^ 



^elLVr Htt^UwIhlrsc"^ sternum which presents two 



