CENTRAL NERVOUS SYSTEM IN VERTEBRATE ANIMALS. 
739 
With Gottsohe (34) the tuberculum cordiforme corresponded to the corpora 
quadrigemina, and the commissure of the tectum was the corpus callosum, as with 
Camper. 
The projecting ridges on the inner contiguous edges of the tecta, he termed the fornix. 
Carus (12) was the first to discover these bodies and also applied this name to 
them, but more on account of their shape, and without any reference to the fornix 
of anthropotomy. 
Gottsohe considered the communication between the two sides of the ventricle of 
the optic lobes, beneath the two ridges above-mentioned, to be the foramen of Monro, 
and the tuberosity on the floor of the ventricle to be the thalamus opticus. 
Treviranus (13), following Camper, homologised these lobes with the cerebral 
hemispheres, the tuberculum cordiforme with the corpora quadrigemina, and the 
tori semicirculares with the corpora striata combined with the thalami optici. Sub- 
sequently (29) slightly changing his interpretation, he compared them to the posterior 
part only of the hemispheres combined with the corpora quadrigemina. Many 
anatomists, with better reason, considered these lobes as the equivalent of the 
corpora bigemina in birds; the first of these was Carus (12), who was followed by 
Tiedemann (15), who came to this conclusion from embryological considerations. 
Serres adopted this opinion on account of the position of the pineal gland and of 
the origin of the nervus patheticus, which, as he remarked, invariably arises between 
the corpora quadrigemina and the cerebellum. 
This author refuted the objection that these bodies in the higher Vertebrata are 
solid, whereas in fishes they are hollow ; by the assertion, that in the embryo of those 
higher Vertebrata they have a cavity in them as in the Teleostei. 
Girgensohn (42), Baudelot (61), and Vulpian (56) also follow this interpretation ; 
the latter having changed from his former opinion (45), in which paper he said that 
they were “le cerveau proprement dit.” 
According to V. Baer these lobes are the “ zwischenhirn ” (thalamencephalon), 
and the tuberculum cordiforme the “ mittelhirn ” (mesencephalon) which in some 
unexplained way had become thrust under the former in the process of development. 
Johannes Muller also followed this opinion ; he considered that these optic lobes 
were equivalent to the corpora quadrigemina conjoined to the “ lobus ventriculi tertii” 
of the foetus. At the point where the tecta arch over the tuberculum cordiforme, just 
described, there is a fissure which communicates with the ventricle of the optic lobe ; 
this Klaatsch (44) considered to be the fissure of Bichat : an opinion which is 
obviously untenable. 
The unpaired ganglion situated behind the optic lobes has almost unanimously been 
looked upon as the cerebellum (fig. 1 , cbl., and figs. 6, 7, and 8). This tuberosity overhangs 
the medulla oblongata and closes in the fourth ventricle ; it varies in shape in different 
■species, being tongue-shaped in Whiting ( Merlangus vulgaris), almost square in Mugil 
cephalus, presents two distinct tuberosities in Labra.x Lupus, and in Scorpcena Porous 
