146 Journal of Compahative Neurologv. 



experiments of von Gudden [" p. 429]. We must refer to 

 Honegger's work ['•' p. 348 ct scq.^ for the discussion of this 

 point. \'icq d'Azyr's bundle arises ['' p. 6^] from that one of 

 the two median niduli that is caudad; it passes up through 

 the thalamus and loses itself in the anterior tubercle. By its 

 side, following Edinger's description [-' p. 6=;], the tegmental 

 bundle of the mammillary body passes dorsad, but soon sepa- 

 rating from its companion, bends caudad, and passing through 

 the tegmentum, can be traced to ganglia lying under the 

 aqueduct. 



Ganglia Habenulcc [Goronowitsch, '' pp. 442,551]. — The 

 habenular ganglia of Acipcnscr are not symmetrically devel- 

 oped; the right one is noticeably larger than the left. In 

 cross-section the dorsal corner of the thalamus (into which 

 the optic fibres run) contains the habenular ganglion. Some 

 fibres, running into this, can be traced from the vertical 

 rons of small cells lying between the ventrical epithelial and 

 the granular substance. It is almost certain that these 

 ganglia are homologues of those in the higher vertebrates, 

 for in both types the connections with Meynert's bundle are 

 very similar. In Aniiurus [Wright, '' p. 32] the ganglia 

 have the same position and connections. Mayser thinks that 

 in the Tclcosts the bundle that passes along the upper edge 

 of the wall of the third ventricle is homologous to the taenia 

 of the higher vertebrates. These ganglia in the amphibians 

 lie just behind the supra-commissura, and send out fibres 

 forming a conspicuous tract (Meynert's) in all of these 

 animals. Each of the ganglia habenular in the mammals 

 gives off fibres which go to form Meynert's bundle. This 

 connection is an intimate one [von Gudden, ' p. 423]. 



Interpeduncular Ganglion [von Gudden, ' p. 424 et seq.]. 

 — In the rabbit this. consists of ground substance, which is 

 an aggregation of more or less sharply defined nests of fine- 

 fibred, band-shaped bundles, somewhat like the glomeruli of 

 the olfactory bulb. Besides this, there are small rounded or 

 spindle-shaped ganglionic cells. The bundle of Meynert 



