- Prof. Clifford Groves: [Angry at skeptical scientists hearing his lecture] Let me assume you, for want of your own understanding, that man's boasting pride in his alleged advancement is based on one hollow precept that is his ego.
- Prof. Clifford Groves: The world's gone completely mad. Sometimes I think I'm the only rational being left in it... one person telling a fairy tale and the other one believing it.
- State Police Chief: [after shooting at the monster] Winged him! It's a big country but too small for that bird!
- [last lines]
- Dr. Ross Harkness: [referring to Groves] And for months Professor Grove was laboring to perfect his discovery... He experimented on himself... Here lies the result. We mustn't think of him too harshy... The things he did... and they were terrible. All of us are capable of doing when we give free play to the basis which is a part of everyone... He tampered with things beyond his province. Beyond what any man should do... And if it was madness... well... Those whom the gods would destory they... they first make mad.