1. Analysis of records from the Storrs Contest, the Harper Adams Trials, and a farm flock indicate an increase of tumors in the second half of the pullet year (May through October) over the first half (November through April).
2. Some evidence seems to indicate that heavy antecedent egg production is associated with a rise in tumor rate.
3. The normal annual tumor rate for fowls between the ages of 6 and 18 months is about 2 or 3 per cent.
4. The appearance of tumors in "epidemic" form probably indicates that the neoplasms found differ in etiology from those upon which the normal rate is based.