Table 2.

Average number of axons, their areas and diameters during development of the saccular and papillar branches of the Xenopus laevis VIIIth cranial nerve.

	Average Number of Axons^*
AXON AREA (μm²):	≤ 0.79	>0.79 – 3.14	>3.14 – 7.07	>7.07 – 19.63	>19.63 – 38.48	>38.48 – 78.54	>78.54
AXON DIAMETER (μm):	≤ 1	> 1 – 2	>2 – 3	>3 – 5	>5 – 7	>7 – 10	> 10
Sacculus
Stage 52	2.4 ± 0.7	48.6 ± 16.8	59.2 ± 8.3	38.6 ± 10.3	25.4 ± 5.8	7.2 ± 1.6	0.2 ± 0.2
(n = 5)	(1.3%)	(26.8%)	(32.6%)	(21.3%)	(14.0%)	(4.0%)	(0.1%)
Juvenile	0	40.6 ± 4.1	250.8 ± 19.4	230.6 ± 15.1	41.8 ± 3.9	37.6 ± 2.2	1.8 ± 0.7
(n = 5)	-	(6.7%)	(41.6%)	(38.2%)	(6.9%)	(6.2%)	(0.3%)
Adult	0	8.6 ± 1.5	134.4 ± 17.3	367.2 ± 20.2	145.8 ± 18.7	35.0 ± 5.1	14.0 ± 2.5
(n = 5)	-	(1.2%)	(19.1%)	(52.1%)	(20.7%)	(5.0%)	(2.0%)

Amphibian Papilla
Stage 52	3.3 ± 1.9	22.0 ± 2.1	14.2 ± 1.9	1.7 ± 0.5	0	0	0
(n = 6)	(8.1%)	(53.4%)	(34.4%)	(4.0%)	-	-	-
Juvenile	15.0 ± 1.7	215.0 ± 11.1	201.6 ± 15.0	153.0 ± 10.4	1.2 ± 0.5	0	0
(n = 5)	(2.6%)	(36.7%)	(34.4%)	(26.1%)	(0.2%)	-	-
Adult	0	2.8 ± 1.9	40.0 ± 22.2	220.8 ± 50.8	164.2 ± 33.8	75.8 ± 25.0	5.2 ± 1.9
(n = 5)	-	(0.6%)	(7.9%)	(43.4%)	(32.3%)	(14.9%)	(1.0%)

Basilar Papilla
Stage 52	9.0 ± 1.6	43.2 ± 4.6	14.2 ± 2.5	3.0 ± 1.6	0	0	0
(n = 6)	(13.0%)	(62.3%)	(20.4%)	(4.3%)	-	-	-
Juvenile	1.8 ± 1.0	41.4 ± 19.0	109.6 ± 15.8	137.0 ± 20.3	2.8 ± 1.5	0	0
(n = 5)	(0.6%)	(14.1%)	(37.5%)	(46.8%)	(1.0%)	-	-
Adult	0	2.4 ± 0.5	20.0 ± 4.3	236.2 ± 19.2	54.0 ± 20.6	3.4 ± 2.2	0
(n = 5)	-	(0.8%)	(6.3%)	(74.7%)	(17.1%)	(1.1%)	-

Axons are grouped into seven bins by area (μm²). The axonal areas from analyzed nerve branch sections were grouped into bins and then data for each bin was averaged for each age for each of the three branches. The axon diameters (μm) corresponding to the bin axon areas were calculated from the equation, area = πr². The relative number of axons for each branch at each age in a given bin are represented by percentages under the data for numbers of axons.