414 



ANNUAL REPORT SMITHSONIAN INSTITUTION, 1912. 



and though the ends in view have been quite different the investi- 

 gations have led to essentially similar results. The surgeons, who 

 for a long time have transplanted various organs and grafted different 

 tissues, bits of skin among others, have sought to prolong the period 

 during which the grafts may be preserved alive from the time they 

 are taken from the parent individual until they are implanted either 



upon the same subject or upon 

 another. The physiologists have 

 attempted to isolate certain organs 

 and preserve them alive for some 

 time in order to simplify their ex- 

 periments by suppressing the com- 

 plex action of the nervous system 

 and of glands which often render 

 difficult a proper interpretation of 

 the experiments. The cytologists 

 have tried to preserve cells alive 

 outside the organism in more sim- 

 ple and well defined conditions. 

 These various efforts have already 

 given, as we shall see, very excel- 

 lent results both as regards the the- 

 oretical knowledge of vital phenom- 

 ena and for the practice of surgery. 

 It has been possible to preserve 

 for more or less time many organs 

 in a living condition when detached 

 from the organism. The organ first 

 tried and which has been most fre- 

 quently and completely investi- 

 gated is the heart. This is because 

 of its resistance to any arrest of the 

 circulation and also because its sur- 



FiG.l.-TheapparatasofKroneckerforthestudy yjyj^l jg easily shown by its COntraC- 

 of tho heart of the frog when removed from the "^ ,^ i^ , -u I, 



animal, h, c, Tubes containing defilirinated tlllty. in man thO HCart Has becn 



blood; %, cock for distribution of the same; ^^^^ ^^ -^^^^ Spontaneously and com- 



T, cup containing the isolated heart fixed upon • , pl ill 



the end of a two-way canula; 7(2, cock upon an pletoly 25 mmutes alter a legal dC- 

 overflow tube communicating with a float ma- capitation (Rcuard and Loye, 1S87), 



and by massage of the organ its beat- 

 ing may be restored after it has been arrested for 40 minutes (Rohn, 

 1909). The heart of the dog has been known to beat 96 hours after 

 death, that of the tortoise for 8 days, and Burrows (1911) observed 

 the heart of an embryo chick to beat for 3 days after its removal. 



By irrigation of the heart and especially of its coronary vessels 

 the period of survival may be much prolonged. 



