Seasonal Weight and Cytological Changes in the Fat Bodies and Liver of the Iguanid Lizard Sceloporus jarrovi Cope

vival. Fat bodies reach maximum sizes in autumn at the start of vitellogenesis and minimal sizes in late spring. Females have larger fat bodies than males prior to vitellogenesis. Extreme depletion of fat bodies in early spring indicates they are used as an energy source for winter survival. The liver undergoes an autumn hypertrophy in females but not in males. Electron micrographs from autumn females revealed an abundance of cytoplasmic lipid droplets which are presumably utilized during vitellogenesis. These droplets are essentially gone by spring. Livers in females