THE RELATION OF ENDOCRINE FEEDING TO REGENERATION, GROWTH AND EGG CAPSULE PRODUCTION IN PLANARIA MACULATA

¹ From the Department of Biology, Washington Square College, New York University and the College of the City of New York

1. Individuals of Planaria maculata were fed on abundant, exclusive diets of beef liver, anterior lobe of the pituitary and thyroid glands. Others were given aqueous extracts of the glands or were completely starved.

2. No significant differences were noted in the head regeneration time of the gland-fed animals following each of five amputations of the anterior region.

3. Decapitated animals which were starved and those which were kept on the aqueous extract diet and which showed starvation symptoms regenerated more slowly than those which were fed the fresh glands. There appeared to be a correlation between the rate of regeneration and the initial size of the animals.

4. Thyroid-fed individuals increased in size but to a lesser extent than the liver and pituitary-fed forms. All were in excellent condition following four decapitations. Individuals newly emerged from capsules also increased in size when fed thyroid gland exclusively.

5. Liver-fed animals produced a greater number of egg capsules than any of the others. The starved and extract-treated forms, with the exception of a single capsule by the Liver L Aqueous Extract set, produced no capsules.