Akodon longipilis October 23- Lago Moreno. 101 traps last night in dense bamboo/coihue/cipres caught 1 Oryzomys and 12 Ako longi. 4 female Akos and 8 males. Three of the males saved alive to send to Piantanida and one kept for stud (7467). The two females dissected were large adults, vaginas open and muscular, ovaries with large pink follicles, not blister-clear so maybe they are early corpora lutea. Three other females, two of them with open vaginas, were kept alive for smears etc. 7466 F Adult, vagina open, caged with M 7467 7467 M adult caged with 7466 7468 F Adult, vagina open, caged alone 7469 F Adult, vagina not open but almost open (or recently closed), caged alone. October 25. Bariloche. Sent Martha Piantanida 3 unnumbered males from Llao Llao and one female (# ). November 3- Bariloche. The male caged with 7466 has wasted away and after several hours moribund but still warmish I killed him. Maybe the adult males die after breeding like Sminthopsis? Martha Piantanida's captive males died also. Massoia claimed that one never found longipilis with worn-out teeth. I have found a few, but maybe they were all females? November 7- The thought occurs that the excess corpora lutea might be derived from successive ovulations as in the mink. Those females today with beautiful pink corpora lutea that matched the number of embryos would be individuals that implanted promptly with additional ovulations. Therefore CL/fetus counts of the early pregnancies should match, whereas later pregnancies should have accumulated CL. The alternative explanation, that the excess CL are just left over from sterile cycles is negated by the previous finding of fertilized ova in the oviducts of many of such females. November 10- good sample from Llao Llao last night showed one late pregnant individual and the rest ovulated but not visibly pregnant; in fact, not advanced from our previous visit here.