Table S1.

Classification of ganglia

Size	Volume, voxels	Volume, μm3	Equivalent spherical radius, μm	No. of pores
Small ganglion*	5000	$2.3\times {10}^5$	38	0.2
Medium ganglion*	${10}^5$	$4.7\times {10}^6$	103	3
Large ganglion*	${10}^7$	$4.7\times {10}^8$	481	300
Total pore volume	$1.64\times {10}^8$	$7.7\times {10}^9$	1,222	5,000
Mean pore volume	$3\times {10}^4$	$1.4\times {10}^6$	69	1

^*Lower bound on volume.