The essential findings of these experiments may be summarized as follows:
The estrogenic hormone after being given for 1 week slows up the spread of India ink but allows it to reach and exceed a normal spread after 24 hours.
After injections of the estrogenic hormone for 3 weeks the spread of India ink is much less than in the control animals.
The resistance of the rabbit to vaccinia is increased if the rabbit has been castrated and then given the estrogenic hormone for a period of 3 weeks before being vaccinated.
At the present time nothing can be said about the action of the gonadotropic hormone on India ink, as the experiments did not agree.