QUANTITATIVE UNTERSUCHUNGEN AM EMBRYONALEN CEPHALOPODEN-ZNS 1119 



the higher motor centers are larger, in addition the optic lobes are observed to 

 ibe enlarged in Sepia officinalis and Rossia sp. 



Teuthoidea. In Teuthoids as in Sepioids the same lobes are relatively small at 

 ; :he moment of hatching-vertical lobe, brachial lobe and pallio-visceral lobe. 

 j\n exception is the optic lobe, which is much less developed in Teuthoids. This 

 s a characteristic of early hatching larvae. 



As might be expected, comparison of higher associative centers (vertical and 

 ;ubfrontal lobes) shows that structures modem in terms of phylogeny are ge- 

 lerally little developed. This is true of the brachial lobe too. 



We calculated the indices of cerebralisation following Wirz (1959). Octopus 

 migaris, Eledone cirrosa and Sepia officinalis are the three highest cerebralized 

 ..pecies. They show the highest indices at the moment of hatching, regardless 

 )f their state of development. 



VERZEICHNIS DER ABKURZUNGEN 



^bucc Arteria buccalis 



Tbp-pv Connectivum basale posterius-pallioviscerale 

 Tbs-br » buccale superius-brachiale 



"fi-br » frontale inferius-brachiale 



ib » interbuccale 



so Commissura supraosophagealis des Lbr 



Dottergang 



Ganglion buccale inferius 

 » gastricum 

 » opticum 

 » subradulare 

 » stellare 

 Lobus accessorius 

 ba » basalis anterior 



bp » basalis posterior 



br » brachialis 



bs » buccalis superior 



» frontalis inferior 

 » frontalis superior 

 » pedalis 

 » pallio-visceralis 

 » subfrontalis 

 » subverticalis 

 v » verticalis 



ax Maxilla 

 ai Nervus antorbitalis inferior 



» » superior 



» brachialis 



