en extinct. Haploids don't reproduce, and the only
way the diploid number of chromosomes can be kept is to replace those
lost by maturation division of the ovum. You might be able to keep the
diploid number by using immature ova, but the fertilization technique
would be far more complex than the simple uterine injections you use at
Hillside Station."

Douglas looked at him blankly.

"Besides," Kennon added, "I have a microscope. I checked your so-called
fertilizing solution. I found spermatozoa, and spermatozoa only come
from males. What's more, the males have to be the same species as the
females or fertilization will not take place. So there must be male
Lani. Nothing else fits. You've been using artificial insemination
on the main-island Lani. And from the way this place is guarded, it's
obvious that here is your stud farm."

Douglas shrugged and spread his hands in a gesture of resignation. "I
suppose," he said, "that's the way Old Doc found out too. We never told
him, but he knew before he ever came out here."

"The only thing that puzzles me," Kennon went on, "is how you managed to
eliminate the Y-chromosome carriers within the sperm."

"Eh?"

"The male sex-determinant. Half the sperm carry it, but so far as I
know, there's never been a male born on the main island."

"Oh--that. It's something that's done in the labs here. Probably one of
the technicians could tell you. It's called electro--electro freezing
or something like that."

"Electrodiaphoresis?"

Douglas nodded. "That sounds like it. I don't know anything about
it. One of Grandfather's men did the basic work. We just follow
instructions." He shrugged. "Well--since you know the secret there's no
sense in hiding the bodies. Come along and tell me what's wrong."

It was a peculiar feeling to walk down the row of cubical rooms with
their barred doors. The whole area reminded him of a historical novel,
of the prisons of early human history where men confined other men for
infractions of social customs. The grimness of the place was appalling.
The male Lani--impressive in their physical development--were in
miserable condition, nauseated, green-faced, retching. The sickening
odors of vomit and diarrhea hung heavily on the air. Douglas coughed and
held a square of cloth to his face, and even Kennon, strong-stomached
as he was, could feel his viscera twitch in sympathy with the caged
sufferers.

"Great Fleming, man!" Kennon exploded. "You can't keep