TRANSPLANTATION INTO MAMMARY FAT PADS 569 



the development of mammary cancer in mice, but also for other studies where the fate 

 of small fragments of tissues is to be followed in the living animal. There appears to 

 be nothing special about mammary fat per se as a transplantation site, other than in 

 its great mechanical convenience. Limited observations indicate that other accumu- 

 lations of adipose tissue (perirenal, perigonadal, and the like) can also serve as sites 

 for receipt of tissue. To a certain extent, one can look upon transplantation into fat 

 pads as providing a kind of organ culture in vivo. 



