another と the other の使い分け

“another”　は、「もう１つ （追加の１つ）」を意味します。
“the other”　は、「現在言及しているもの以外の、１つのもの」を意味します。

“another”　の例

• One rat was dosed with the drug. As a back up, another rat was given the same dose, but housed separately.
• Immediately after dosing, one rat out of three in the high-dose group became moribund, and then another soon after. By one hour after dosing, all three had died.
• At the dose administered, external abnormalities were observed in 7 of 11 fetuses from one dam, and 1 of 13 fetuses from another.
• Although the reason for its presence was not clear, the drug was also detected in the plasma of the control rats in another study of this compound.

“the other”　 の例

• Out of two rats, one was dosed with the drug, and one was dosed with the vehicle. The rat dosed with the drug was housed in Building A, and the other in Building B.
• Out of four rats, two were dosed with the drug, and two were dosed with the vehicle. The rats dosed with the drug were housed in Building A, and the others in Building B.