<;K< Mii;. \iMiif.\L nisTKi i;i TIO.V. 



M. Fischer concludes. "Is the doctrine of evolution over- 

 thrown by the facts M. IJarrande li:is ])rodueed !' 1 do not think 

 it. He h;is proved that there existed simony t In- ancient eeph- 

 alopods two-i-rcMt types, which have continued separate dnrin-' 

 the entire period of tlieir existence: but the evolution of each 

 of these types remains extremely probable, and conform 

 observations made upon them. In such matters one canno!. in 

 ell'eci. ask more than a probabilit \ 



Geof/rup/u'rnl l)ixt rihu! ion . 



.Most of the species of Oclopods and the Nautilus are 

 littoral in habit, and have thence been conjectured to enjov 

 bui a limited distribution; and which is held to jnsiily the 

 multiplication of species. This reasoning is. however, falla- 

 cious, as it is well known that many ILtoral mollusks. no! 

 nearly so well provided with means of swimming, have be- 

 come world-wide in distribution.' I shall show hereafter, not 

 only that particular species of Octopus are known to inhabit the 

 shores of distanj countries, but thai a lar^e proportion of <hesc 

 species which have been (list ino-iiishcd by slight and mutable 

 charac!ers. and by their geographical distribution, will probably 

 need lo be united when sufficiently s'udied. This probable ex- 

 tensive distribution of living litionil sjiecies corresponds with 

 observations made upon fossil species of Ammonites. Nautilus 

 and other ch:imlered ovnera. which are proved to have been 

 littoral in habit by their occurrence only in deposits representing 

 ancient sea-shores. Not 10 multiply example's amongst these' 

 fossils, it may be mentioned lliMt NatifiliiK tdntjilr.r occurs in 

 Kui-ope. Kast Indie-s and Texas; that Ammonites Motomagensis 

 is found in Knrope. Kast Indies. N. and S. AlVica and S. 

 America : and that /inrulifrtt r/c'-/'s had even a ii'reat er dist I'ibu- 

 tion. Nevertheless, temperature has been observed to h:ive 

 some elfect upon the distribution of '.he living octopoda of 



Europe, similar bu1 distinguishable forms or species inhabiting 

 its northern seas, from tlio-c <!' ihe Mediterranean. As in Mol- 

 liiscan life Li-enerally. the development of specific forms has been 

 ;jTc:i1est in t ropical wafers. 



* Jour, de Zool, iv, 419, 1877. 



