( 47 ) 
especially its angle and eyes appear above it. With this angle it 
attracts small fish and other animals, and when its prey has come 
sufficiently near, it jumps at it with a jerk of a fin or of its tail, 
and devours it. In doing this, however, it has to take care to keep 
its gill-cavities closed, these being so wide that a swallowed victim 
would be able to escape by this way. 
Accordingly, whenever a prey comes near and gives strong visual 
• stimuli, the facial muscles begin to work, because these stimuli are 
conducted to the facialis-nucleus along the tractus tecto-bulbaris l ). 
The shifting of the facialis-nucleus must therefore depend on the 
force and number of these stimuli, which other fishes do not nearly 
receive to the same extent. 
That the sense of touch of the angle very likely plays no partin 
the catching of the prey, appeared from the slight development of 
the sensory nerves, leading to this organ. 
In connection with the considerable size of the tectum opticum 
and the dorsal position of the eyes of Lophius (which in Gadusand 
Tinea have a lateral position) and their probable power of collabo¬ 
ration (while the field of vision in Gadus and Tinea is for the 
greater part, if not exclusively, unilaterally panoramic), it is also 
striking that part of the abducens-nucleus in Lophius, has already 
assumed a dorsal position, by the side of the coordinating system 
of the posterior , longitudinal bundle. In the other above-named 
Teleosteans, though they are better swimmers, this nucleus lies still 
quite ventrally. 
Summarizing I therefore think the following conclusions may be drawn: 
1. In Lophius piscatorius part of the motor facialis-nucleus is 
displaced towards the tractus tecto-bulbaris, which conducts particu¬ 
larly powerful stimuli from the tectum opticum to the facialis nerve, 
because the sense of sight is well developed and in catching a prey, 
after stimulation of the eye, the gill-cavity must be closed and the 
mouth be opened, by a strong reaction of the particularly strongly 
developed facial muscles. 
2. Contrary to other Teleosteans (Gadus, Tinea) part of the 
abducens-nucleus lies dorsally by the side of the posterior longi¬ 
tudinal bundle, a phenomenon which is more pronounced either 
in animals with a strongly developed and well-coordinated motility 
of the body or in animals with well-coordinated ocular movements. 
3. The musculus levator operculi is here not innervated by the 
facialis-nerve, but by a branch of the vagus. 
J ) It would be^ desirable, to check all this in the living animal, but Lophius 
refuses to take any food in captivity. 
