Table I.

Percent Nuclei Incorporating BrdU

		Mean		SE
Continuous feed
1.5–1.75		9.9		1.0
2.25–2.5		10.5		1.1
3.25–3.5		17.2		1.7
4.75–5		25.8		2.1
6–7		28.6		2.1
Pulse feed
7–7.5		8.4		2.0
14–14.5		7.3		.9
20–20.5		9.7		2.2

Percent of nuclei from the CNS of third instar larvae labeled with BrdU using various feeding regimens. All of the nuclei (60–200) in nine microscope field were counted. DNA incorporated BrdU for 1.5–2.5 hr, as can be seen from the similarity of percent nuclei labeled in these experiments to the percent labeled in the 1.5–2.5 hr continuous-feed experiments. SE, standard error. The first column is hours after the start of BrdU feeding.