Comic Title: World's Finest Comics #151
Publisher: DC (National Periodical Publications, Inc.)
Address: 575 Lexington Avenue, New York, NY
Cover Date: August 1965
On Sale Date: June 10, 1965 Copyright Date June 10, 1965
Source: Library of Congress, Periodicals 1965

Frequency: Monthly, with the exception of Jan., April, July and Oct.
Cover Price: $0.12
Page Count: 32
Editor: Mort Weisinger

Notes:
This issue contains a half-page text feature entitled "Time Trips of the Terrific Trio" which details the time travel adventures of Superman, Batman, and Robin.

Title: "The Infinite Evolutions of Batman and Superman"
Pages: 16

Feature(s):
Superman (of Earth-1)
Batman (of Earth-1)

Writer: Edmond Hamilton
Penciller: Curt Swan
Inker: Sheldon Moldoff

Reprinted In:
Showcase Presents:World's Finest Vol. 3 TPB (2010)
Batman & Superman in World's Finest Comics:The Silver Age Omnibus Vol. 2 HC (2019)

Feature Character(s)

• Superman (last appearance in Superman's Pal, Jimmy Olsen #87; next appearance in Superman #179)
• Batman (last appearance in Batman #173; next appearance in Detective Comics #342)

Supporting Character(s)

• Robin (last appearance in Batman #173; next appearance in Detective Comics #342)
• Lois Lane (last appearance in Action Comics #326; next appearance in Superman #179)
• Perry White (last appearance in Superman's Pal, Jimmy Olsen #86; next appearance in Superman #179)
• Jimmy Olsen (last appearance in Superman's Pal, Jimmy Olsen #87; next appearance in Superman #179)

Guest Appearance(s)

• Krypto (last appearance in Superman #177; next appearance in Action Comics #330)

Other Character(s)

• Ral-Than (a Kryptonian scientist; appears in flashback; no further appearances)
• A tribe of cavemen and a race of future men (no further appearances)

Comments:
Part 2: "The Caveman Superman Versus the Future Batman"

Synopsis:
Superman discovers a machine from his home planet Krypton. The machine has been changed into Kryptonite, so he contacts Batman to help him examine it. The machine is an evolution ray created by Ral-Than, a Kryptonian scientist. Batman tests the machine on himself and is transformed into a future man. The evolution process also turns Batman evil. He reverses the ray on Superman, devolving the Man of Steel into a caveman.

Superman begins rampaging as a caveman in Metropolis. Batman makes him travel back in time to the days of real cavemen. Batman then transports himself into the far future. Tiring of the past, Superman returns to hunt for Batman. He finds him in the future and brings him back to the prehistoric time period.

Superman orders Batman to build a device that will change him back to normal. Batman builds the machine, but plans to devolve Superman even further. Krypto, who has tracked Superman to the distant past, prevents the transformation, but is devolved to a feral beast. Superman then forces Batman in front of the ray, returning him to normal. Batman then fixes the machine, so that Superman and Krypto are also restored. Then everyone returns to their own time.