166 



A. S. Parkes 



The second experiment (line two of the table) seemed con- 

 clusive on the point. The homografting of long-stored 

 ovaries into newly ovariectomized young females (line three 

 of the table) and the reciprocal experiment of homografting 

 fresh tissue from young females into the old ovariectomized 



Table I 



Grafting of Long-Frozen Ovarian Tissue into Original Donors or 



Young Ovariectomized Females and of Fresh Ovarian Tissue from 



Young Females into Long-Ovariectomized Old Females 



(Donors all young females approx. 100 g. B. Wt.) 



females (line four of the table) showed clearly that the long- 

 stored tissue, not the old females, was at fault. It must be 

 assumed, therefore, that there had been an undetected 

 breakdown in maintenance of the liquid air flasks, or that 

 the tissue had deteriorated spontaneously during its second 

 year of storage. It has not yet been possible to distinguish 

 between these alternatives. 



Isolated Organs 



In some ways the possibility of long-term preservation of 

 isolated organs is of even greater interest than that of cells 

 or tissues. An approach has been made to this problem by 



