[Altered reproductive behaviour of Trypanosoma musculi after several years of passage in mice (author's transl)].

The modified strain multiplied less in pregnant and in Plasmodium berghei-infected mice, more in heavily infected normal mice, and more or less in weakly infected normal mice. The discordant behaviour in weakly infected mice was due to the occurrence in some animals of a second phase of more rapid increase of the parasitemia. This behaviour could be seen occasionally in the original strain, too. In inbred mice (BALB/cHan) the length of parasitemia clearly depended on inoculum size and height of the developing parasitemia.