Post-flight histological analysis of turtles aboard Zond 7

On the occasion of the flight of Zond 7 four turtles were included in the payload. A detailed histological analysis was carried out upon recovery of the subjects. No gross changes were observed, but the nuclei in the cells of many tissues decreased in volume by a statistically significant amount. This decrease is assumed to correspond to certain changes in function which adapted the animal to space flight conditions. No pathological changes were observed.