"The Coming of Ka-Zar! "
Writer: Stan Lee
Penciller: Jack Kirby
Inker: Chic Stone
Plot: After seeing footage of a "jungle man" and his sabretooth tiger attacking an Antarctic research station, Professor X sends the X-Men to investigate, not because he thinks the jungle man is a mutant, but just because it's been awhile since the X-Men went out on an adventure. In Antarctica, the X-Men discover a tunnel beneath the ice that leads them to a tropical, prehistoric jungle. After marveling at the place, they are attacked by savage Swamp Men. Ka-Zar and Zabu, the jungle man and his tiger, help them fight off the Swamp Men, but not before Marvel Girl and Angel are captured. The remaining X-Men tussle with Ka-Zar because, well, you know, before teaming up with him to defeat the Swamp Men and rescue their teammates. The X-Men depart, having established an uneasy friendship with Ka-Zar.
Firsts and Other Notables: Ka-Zar, Zabu and the Savage Land make their first appearances, all of which go on to become mainstays of the Marvel Universe. This is actually considered the first "modern" appearance of Ka-Zar, as the character is based on a Golden Age character that appeared in pulp magazines tangentially published by Marvel before appearing in comics, technically making him Marvel's oldest original character still in use.
In future appearances, Ka-Zar is notably eloquent, an English gentleman lost in the Savage Land as a teen (as opposed to Tarzan, who was raised by apes). In this story, however, he is simply the "lord of jungle" and speaks with a "me Tarzan, you Jane" dialect.
The Savage Land (not called as such here) is eventually revealed to be a prehistoric wildlife preserve built by aliens. For now, it is merely a mysterious prehistoric jungle buried beneath Antarctica.
A Work in Progress: Iceman uses one of his patented "ice slides" for the first time to bridge a gap in the Savage Land.
Ah, the Silver Age: Ka-Zar wanders Antarctica in only a loincloth. The story even points this out, but doesn't explain how it's possible.
Jean refers to Iceman as a "juvenile Jerry Lewis."
According to this issue, the Savage Land is buried beneath Antarctic ice. Except the sky is a sky and not the underside of an ice dome, or something.
Angel refers to pterodactyls as "birds from the dinosaur era" which isn't quite correct.
Young Love: As has become the standard by now, both Scott and Jean are secretly pining for one another.
It's in the Mail: Why doesn't Iceman slip when he walks?
Apparently, Marvel Girl's constantly changing masks are a result of her being a woman...
The Bullpen seems to be pressed for time:
Teebore's Take: This issue is more significant for its introduction of Ka-Zar and the Savage Land than anything else. While it is refreshing to have a story that doesn't involve Magneto, the Brotherhood or any other mutant villain, one has to wonder why this story is appearing in "X-Men"; the story even goes out of its way to establish that the X-Men are only getting involved as a lark. Still, it's not a bad issue, and it does contain some cool looking Kirby-drawn dinosaurs and mammoths and whatnot.