Additional notes on the cranial nerves of petromyzonts

J. B. Johnston
1908 Journal of Comparative Neurology and Psychology  
WITH THIRTY-ONE FIGURES. In the year 1897 I prepared by the GOLGI method a number of series of sections of the head of Lampetra wilderi. These were used for the study of the brain (1902) and were reviewed in connection with the study .of the components of the cranial nerves in Petromyzon dorsatus (1905). Owing to the fact that certain fibers are impregnated and others not, the GOLGI preparations are not in themselves suitable for a complete study of cranialnerve components and such differences
more » ... ere found between the two species that it was thought best not to incorporate any of the facts from the Lampetra series in the description of the nerves of P. dorsatus. The GOLGI preparations were therefore laid aside with the hope that they could be supplemented by new preparations and the cranial nerves thoroughly gone over by this method. The time for making these new preparations now seems more remote than ever and I have decided to publish certain results which are entirely clear from the preparations in hand. The animals used were adults. The general relations of the cranial nerves may first be reviewed by means of figs. I to 11. These are camera sketches from a series of horizontal sections. The anterior part of the right half of the head is shown, including the first two gill sacs. The figures are not schematized at all except that detail had to be omitted, and in figs. 3 and 8 a little is added from the sections adjacent to those drawn and fig. 1 1 is a reconstruction from several sections. The left half of this figure represents sections fartherventrad than those drawn on the right. The entire series consists of 109 sections and the section drawn is indicated beneath each figure. In all All were taken on their nests just after spawning. Neurological Studies, University of Minnesota, no. 2 .
doi:10.1002/cne.920180603 fatcat:pkk62itvyvdexnh2zxtnlnq4va