658 
Nachdruck verboten. 
The Lateral Sensory Anlage in the Salmon. 
By H. V. Witson and J. E. Marrocgs. 
With 2 Figures. 
It was discovered some years ago by Wınson !) that in Serranus 
the organs of the lateral line, the auditory sac, and the superficial 
sense organs of the head (presumably all) were all derived from a 
common foundation. This common foundation has the shape of a long 
furrow (ectodermic) on the side of the head region. The furrow splits 
into three parts, the posterior part giving rise by division to the or- 
gans of the lateral line, the middle part becoming the auditory sac, 
the anterior part becoming a histologically developed branchial sense 
organ, situated in front of the single gill slit of the embryo, from 
which a (sensory) cord of cells is prolonged forwards. 
MITROPHANOW?) has found that in Selachian embryos the se- 
veral organs just mentioned also arise from a common foundation, and 
Locy*) has likewise ascertained this to be the case in Selachians. 
The Anlage in Selachians is not however a well-marked furrow as in 
Serranus, but only a thickening. There are numerous other differences, 
especially concerning the precise way in which the common Anlage 
splits up. But as regards the chief point, MirropHanow, Locy, and 
WILSON are in accord, agreeing that a common Anlage exists, which 
subsequently divides. 
MirropHANOW”) has also studied in this connection Cyclo- 
stomes, Teleosts, and Amphibia. In the Cyclostomes and Amphibia, 
the common Anlage is a thickening, not very clearly marked. For the 
Teleosts (forms studied not stated) M. follows the account given 
for Serranus. The Anlage in Cyclostomes and Amphibia, according 
to M., divides up into what seem to be the same derivatives as those 
found in the Bass. 
1) The Embryology of the Sea Bass (Serranus atrarius). By Henry 
Ve Witson. Bulletin U. S. Fish Comm., Vol. IX, Washington 1891. 
2) Etude embryogénique sur les Sélaciens. Par Paut Mırroruanow. 
Archives de Zool. exp. et gén., 3e Ser. T. 1, 1893, No. 2. 
3) Contribution to the Structure and Development of the Vertebrate 
Head. By Wm, A. Locr. Journal of Morphology, Vol. XI, No. 3, 1895. 
