Scientific Intelligence — Zoology. 427 



but that a part of them have been destroyed, and have not reached 

 our times. The changes of climate, and the influence of man, have 

 been the causes of these disappearances of species, some of which have 

 taken place at periods too remote to have left any traces in tradition, 

 but others of which are well known, and some are even taking place 

 under our eyes. — Professor Pictet. 



8 . On the Respiratory Apparatus of Birds. By M. Natalis Guillot 

 and M. Sappey. — It is a fact generally admitted, that in birds the 

 air which reaches the lungs is introduced by permanent openings, in 

 the cavity of the abdomen, in the bones, and in diverse parts of the 

 body. M. Guillot has endeavoured to determine the position of the 

 aerial reservoirs, and to shew that it is an error to believe that the 

 air can be introduced into all the parts of the body of the animal. 



He distinguishes the thoracic aerial reservoir and the abdominal 

 reservoir. The latter is composed of two large spheroidal bladders, 

 formed by a membrane of extreme tenuity, and separated by the me- 

 sentery and the mass of the intestines. Their origin is towards the 

 base of the breast, on a level with the last rib, where we perceive an 

 elongation of the lung pierced with many openings. The interior of 

 these receptacles does not communicate with the peritoneum ; they are 

 bladders full of air, and nothing more ; they are not celluUr, like the 

 thoracic reservoir. 



When we place a living bird under water, and keep it there in 

 such a manner that the respiration is free, we may open the perito- 

 neum, without a single bubble of air making its escape. Neither does 

 any appear by cutting the cellular tissue, by raising the skin, and 

 cutting the muscular masses. The same thing does not always take 

 place after the death of the bird, for then, according to M. Guillot, 

 gaseous bubbles arise from the blood. This anatomist thence con- 

 cludes, that the air maintained by the envelopes of the two reservoirs 

 above mentioned, cannot enter but into the bones, and that it neither 

 enters into the peritoneum nor the cellular tissue ; in a word, that it 

 cannot diffuse itself through all the parts of the body during the life 

 of the animal. 



In connection with this communication, M. Serres referred to the 

 analogous investigations of M. Sappey, demonstrator in the anato- 

 mical school of the hospitals ; and this latter anatomist himself read 

 a memoir to the Academy of Sciences (9th and 23d July 1846) on 

 the same subject. The conclusions of his memoir are the following : 

 Istf There is no pleura in birds; 2d, The membrane which has 

 been described under that name, is formed by the inferior bronchia 

 of the lungs ; 3(f , All the bronchial ramifications are periferal, and 

 produce, by leaning against each other, a true aeriferous envelope ; 

 4th, Not only does a diaphragm exist in birds, but it is an essential 

 agent in the pulmonary dilatation ; 6th, Observation rejects the ex- 

 istence of full cells, the communication of the respiratory apparatus 

 with the muscles, the cellular tissue, and the feathers ; 6th, The 



