436 FANCIED FUNCTIONS OF 



animal may continue quietly to eat till the stomach is enormously 

 distended ; and this, no doubt, because the stomach is deprived 

 of its sensibility so that its distension is no longer felt, and the 

 animal, though it must at the same time be insensible to the pangs 

 of hunger in it, continues to eat from habit or the pleasure of 

 masticating. h We need not suppose its muscular power to be 

 destroyed by the injury of the nervous system, because continued 

 eating must produce over-distension, though the power of con- 

 traction be, before the over-distension, unimpaired. Dr. Philip 

 maintains that the injury suppresses the secretion of gastric juice 

 and digestion; but Drs. Leuret and Lassaigne assert that di- 

 gestion proceeds as before, though even six inches of each nerve 

 be removed in the horse ; and Sir B. Brodie and Dr. Magendie 

 found digestion uninfluenced, if the division was made, not in 

 the neck, but close to the stomach ; and, again, Dr. Magendie 

 found digestion proceed in brutes after the removal of the cere- 

 brum and cerebellum. (See suprti, p. 87.) 



The division or ligature of the pneumono-gastric nerve has 

 been a favourite experiment with endless vivisectors from the 

 time of Galen himself; but I believe that Dr. Le Gallois was the 

 first to point out that the blood experiences no longer the 

 chemical changes in the lungs, but their air-cells become filled 

 with frothy mucus, their substance gorged with blood, and their 

 surface marked with dark patches. The engorgement and black 

 patches result, however, merely from the want of changes in the 

 blood ; and this partly from the animal scarcely feeling the want 

 of respiration ; so that in a rabbit the respirations instantly become 

 very slow, an instance analogous to the slow breathing of sleep 

 and the much slower of apoplexy, in which states the want of 

 respiration is less perfectly felt ; and partly from the stay of all 

 the mucus in the air-cells and tubes, which, like the stomach, 

 have lost their sensibility, so that, the quantity of mucus not being 



h Dr. Le Gallois found that, after this division, a guinea-pig would eat, from 

 habit or the pleasure of the mouth, till its belly was as long as its body ; and the 

 O3sophagus would also become distended, sensation being lost and muscular 

 power paralysed. Dr. Brachet kept animals without food, and they showed all 

 the signs of hunger. He divided the pneumono-gastric, and then offered them 

 food. But they were now indifferent to it ; and, on being enticed to eat it, they 

 ate on till the stomach would hold no more and the oesophagus was filled. 

 The cessation of muscular action might be the result of merely the loss of sen- 

 sibility. 



