42 



their medulla oblongata, are in full life. It is so much so that 

 if they are compared to frogs possessing that nervous centre, 

 they resist etherisation longer, and also live longer after the 

 ablation of the heart. 



II. The greatest differences exist in the duration of life, after 

 the removal of the medulla oblongata, in animals of different 

 species, as will be seen in the following table, where the maxi- 

 mum duration of life is indicated in sixty different species of 

 animals : 



Classes. Species. 



f Salamanders 



Amphibia. ) Frogs ..... 

 ( Toads . 



Duration of life. 

 More than 4 months. 

 4 to 5 weeks. 



Reptilia. 



Fishes. 



Birds. 



Tortoises . . . . 9 to 10 days. 



Snakes . , . . 6 to 7 days. 



Lizards . . . . 4 to 6 days. 



Eel 6 days. 



Pike, carp, tench, eel pout, barbel 3 days. 



Perch, gudgeon and others . 25 to 40 hours. 



Sparrowhawk (newly born) . 21 minutes. 



Magpie do. . 19 minutes. 



Sparrow do. . 17 minutes. 



Sparrow, yellowhammer, linnet, pi- 

 geon, fowl, duck, pintaw, par- 



tridge,'moor-hen, turtle-dove (adult) 2| to 3 minutes. 



29 hours. 

 23 hours. 

 46 minutes. 

 41 minutes. 

 34 minutes. 

 6 minutes. 



4 minutes. 



c Dormouse (during hybernation) 

 Hedgehog ditto 



Bull-dog (newly born) 

 Cat ditto 



Mammals.* j Rabbit ditto 

 Guinea-pig ditto 

 Dormouse and Hedgehog awaken in 



summer .... 

 Cat, rabbit,guinea-pig and dog (adult) 3 to 3| minutes. 



The preceding table shows that after the removal of the me- 

 dulla oblongata, in different species of animals, the duration of 

 life may be reckoned by months for batrachia, by weeks for some 

 reptilia, by days for other reptilia and for fishes, by hours for 



* Pulmonary insufflation has been used only for the dormouse and 

 hedgehog during hybernation. 



