STRANDED AT LONGNIDDRY. 235 



the liver. In the coil of intestine from the adolescent animal, from which 

 fig. 32 was taken, a vein larger than the human inferior cava, ran close and 

 parallel to the great moniliform artery of the intestine, and received numerous 

 veins, the rootlets of which took their origin within the coats of the gut. In 

 the foetus a vein lay along with the artery in the expanded part of the me- 

 sentery. 



At the upper part of the cavity of the thorax in the foetus, close to the 

 apex of the pericardium, a well-defined, though small, thymus gland was found. 

 It was subdivided into two lobes, each of which was brown in colour, thin, 

 and flattened in form, and 5 inches in length by 4f inches in its greatest 

 breadth. The lobes were subdivided into distinct lobules by intermediate con- 

 nective tissue, and they received numerous blood-vessels. In proportion to 

 the size of the animal the gland was obviously smaller than might have been 

 anticipated. The thyroid gland, supra-renal capsules and spleen were not re- 

 cognised during the dissection. 



Organs of Respiration. — When the cavity of the thorax was opened into, by 

 the removal of the inferior wall, the lungs were exposed. In the foetus each 

 lung was an elongated, flattened organ 2 feet 8 inches in length. It was in- 

 vested by a distinct and smooth pleura, and was not subdivided into lobes by 

 fissures. A similar absence of fissures and lobes I have also seen in the lung 

 of B. rostrata. The pulmonary artery, veins, and bronchus entered its substance 

 through the hilum on its mediastinal surface. When the lung was removed and 

 washed with a jet of water, the softened pulmonary substance broke down, and was 

 washed away, and the arrangement of the intra-pulmonic part of the bronchus 

 could be seen. This tube, as a rule, branched in a dichotomous manner, though 

 collateral offsets sometimes proceeded from it. It was accompanied by the pul- 

 monary and bronchial arteries, and by bronchial nerves of some size. 



The cartilaginous framework was much more perfect than in the human 

 bronchus. The tube was hooped with cartilaginous, spirally arranged, ring-like 

 plates ; in the larger tubes usually not more than once and a-half, but in the 

 smaller tubes a greater number of times (fig. 35). Sometimes in these latter the 

 cartilage formed perfect rings, and both in them and in the larger tubes 

 the cartilaginous plates not unfrequently bifurcated. The branching of 

 the plates was always well-seen at the angle of the bifurcation of the tubes. 

 The plates were invested by a well-defined perichondrium. The hoop-like and 

 spiral coils of these cartilaginous plates have an important office in connection 

 with the respiratory process in this animal. They not only aid in keeping the 

 tubes open, but, by their elasticity, aid in the recoil of the lung during the great 

 expiratory effort which the whale makes in the act of blowing. The diameter 

 of the right bronchus in the foetus was 2 inches, that of the left 2^ inches ; in 

 the mother one of the bronchi was 7 inches in diameter. 



