In vivo and in vitro frequencies of muscle cells and M lineage cells in L1 larvae.

1In vivo frequencies were calculated from Sulston and Horvitz [19] based on cell numbers at hatching.2In vitro frequencies were measured by counting cells in 5 to 8 random fields of cells plated on peanut lectin one day after isolation. Values given as mean ± error (cells counted, no. of trials).