Pearson-1989 31 Abrothrix longipilis October 17 - Bariloche. Caught 10 yesterday on the Llao Llao Peninsula. 5 of the males had large testes and accessories, and 3 of these had lots of zoa in smears of the epidid. The other male was caged with a female with cornified smear. All 4 females had open vaginas. Two dissected had distinct corpora lutea, no zoa in smears, one of them with leucocytes and one with nucleated epithlial cells and cornified cells. One caged with male had nucleated smear, other caged alone had cornified smear. The pair did not mate overnight. October 23- Caught 2 Akodon olivaceus today and noticed that they squeak when handled, whereas longipilis does not. A helpful field character. December 11 - A male killed by cervical separation yesterday had a white rubbery plug of semen extruding from the penis. This suggests that Abrothrix is capable pf forming a vaginal plug, and the fact that we have never? found a plug in a female suggests that they do very little copulating. December 18 - Arroyo Casa de Piedra. 54 Shermans caught 10 Ako longi, 4 Oryzomys, and 1 Aulisco. One adult longi escaped, leaving 3 youngish males (but not juvenile), 4 adult males, and 2 youngish females with open vaginas. Smears of the females not estrous, no zoa.