ORGANS AND LIVING TISSUES LEGENDRE. 417 



vessels upon wliicli they were set. In 1909 Carrel removed the left 

 kidney from a bitch, kept it out of the body for 50 minutes, and then 

 replaced it; the extirpation of the other Iddney did not cause the 

 death of the animal, wliich remained for more than a year normal and 

 in good health, thus proving the success of the graft. In 1910 Carrel 

 succeeded with, similar experiments on the spleen. 



These last examples are quite too few to enable us to arrive at a 

 positive conclusion. Scattered as they are, not yet repeated and 

 checked by all the technical methods at our disposal, they furnish 

 only an indication of the possibility of the survival of organs as 

 delicate as the spleen and kidneys for some time after removal from 

 the body. 



Even the nervous system is not exempt from preservation outside 

 of the organism. As early as 1885 Laborde showed that in a human 

 head severed from the body artificial circulation commenced 20 

 minutes after the execution produced no movement, yet the cerebral 

 cortex remained excitable bj^ electricity for 50 minutes; in the case of 

 another criminal cerebral excitabiHty was preserved for SO minutes 

 without transfusion. In the dog, Loye observed the excitabihty to 

 persist for 7 minutes; Brown-Sequard (1858) saw after 10 minutes 

 spontaneous movements of the eyes and the face; Guthrie, Pike, and 

 Stewart (1906) with artificial circulation observed reflex movements 

 for 19 minutes, the corneal reflex for 27 minutes, respiratory move- 

 ments for liaK an hour. In fishes Kuhabko preserved for several 

 hours the activity of the nerve centers by circulatmg an artificial 

 serum through the head ; he observed that the centers of the cerebral 

 cortex lose their excitability more quickly than those of the spinal 

 cord; in the latter the respiratory center and that for the regulation 

 of the heart show different degrees of vitality. 



In frogs it has been known * since the time of Galvani (1781) that 

 the liind legs of a skinned frog, connected b}^ means of the sciatic 

 nerves alone to a segment of the spinal cord, remaiaed excitable for 

 some houi-s. This very important experiment has been repeated 

 many times and has led to veiy significant results: The discovery of 

 the electro-motor property of muscular tissue and electric variation 

 during its contraction (^latteucci, Du Bois-Reymond, 1837-1843). 

 After that, Tyschetzky (1870), Biedermann (1883), Gad (1884), 

 Uschinsky (1885) preserved for some time the spinal cords of frogs 

 entirely removed from the body, in order to study in them the 

 effects of electric currents. Finally, quite recently (1907-1911), 

 Baglioni and his assistants have succeeded in isolating the entire 

 cerebro-spinal axis of the toad (fig. 3, ])1. 1) and preserving it alive 

 for 31 hours and 35 minutes in artificial serum. 



• Swammerdani had already In the seventeenth century Isolated a frog's foot with Its attached sclatio 

 nerve. 



