Surrounding the grey matter is white matter, which consists of the myelinated axons of various neurons.

灰质周围的是白质，由有髓鞘的神经元轴突构成。

The white matter consists of myelinated axons, which are separated into tracts that carry information to and from the brain.

白质由有髓鞘的轴突组成，它们被分成若干神经束，负责向大脑传递以及从大脑向其他部位传递信息。

And although a big fissure separates the left and right hemispheres, the two halves communicate, through a series of myelinated axon fibers called the corpus callosum.

虽然左右半球之间有一条大裂缝，但这两半通过一系列有髓的轴突纤维——也就是所谓的胫骨体——进行交流。