. The anatomy of the central nervous system of man and of vertebrates in general. Neuroanatomy; Central Nervous System. 120 ANATOMY OF THE CENTEAL NERVOUS SYSTEM. Since the optic tract enters the frontal end of the midbrain, one will meet it only in sections which are cut far forward. Such a section (as shown in Fig. 70) encroaches upon the interbrain. The Tectum mesencephali is, in all lower vertebrates, brought into intimate relations with the great nuclei of the interbrain (thalamen- cephalon) through a large bundle: the Tractus tedo-tJialamicus. The bundle is so large that it will doubtles
. The anatomy of the central nervous system of man and of vertebrates in general. Neuroanatomy; Central Nervous System. 120 ANATOMY OF THE CENTEAL NERVOUS SYSTEM. Since the optic tract enters the frontal end of the midbrain, one will meet it only in sections which are cut far forward. Such a section (as shown in Fig. 70) encroaches upon the interbrain. The Tectum mesencephali is, in all lower vertebrates, brought into intimate relations with the great nuclei of the interbrain (thalamen- cephalon) through a large bundle: the Tractus tedo-tJialamicus. The bundle is so large that it will doubtless be found in mammals also. It is lost between the layers of the roof. The cerebral connections probably exist in reptiles; in birds and mammals, however, its existence is certain. Important in the investigation of the brain of lower vertebrates is the large-celled roof-nucleus (DacJihern). The nucleus in question lies close on. Fig. 71.—Sagittal section of a lizard-brain, showing the position of the nuc. lat. mesencephali; also showing well the different bundles of the Opticus and the course of the fibers from the deep medullary stratum into the fillet. either side of the median line, but does not occupy the whole length of the roof. It is not present in mammals, but one meets there a group of quite similar cells, which degeneration-experiments have shown to belong to the fiber-system of the Trigeminus: Eaclix mesencephalica Nervi V. It has not been demonstrated, however, that the origin of the midbrain-root of the Fifth nerve is a homologue of the DachJcern in question. The basis of the midbrain is distinguished by the numerous already described decussations which lie in it, but the fact that several important bundles pass into it from the interbrain, and finally by the presence of several separate Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrat
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