152 POPULATIONS OF THE SEA 



These static patterns, moreover, have dynamic and historic 

 causes of such complexity that only the boldest have dared confront 

 them, and they too commonly with extraneous and weakly 

 documented hypotheses — frequently repeated in substantiation of 

 themselves after cycling through other and unfamiliar disciplines. 

 The results of such circular reasoning are well illustrated by 

 various ad hoc land bridges, whose unbridled rising and sinking 

 in the late nineteenth and early twentieth centuries explained 

 alike the similarities of geographically distant biotas, and the 

 dissimilarities of neighboring ones, both at sea and on land. 

 Handlirsch (1937) and Schmidt (1955) have effectively demolished 

 the general application of this now diminishingly popular mech- 

 anism (see Croizat, 1958, for the opposite view), which, for the 

 moment, merely illustrates the need for verifiable interpretive 

 principles and generalizations. 



Modern marine biogeography at least has the advantage of 

 recognized ancestry (Forbes, 1844; Schmarda, 1853; Forbes and 

 Godwin-Austen, 1859; Regnard, 1891; Ortmann, 1896; Petersen, 

 1914, 1915a, b; Ekman, 1953; Peres and Picard, 1955; Peres, 1957; 

 Hedgpeth, 1957b-d). Even the parentage of paleobiogeography is 

 obscure, howe\'cr. 



D'Orbigny, who was more sensitive to the qualities of his 

 legitimate scientific children (Heron- Allen, 1917), devoted two 

 pages of his famous Coiirs elementaire, etc. (1849, Pt. 1, pp. 6-7) 

 to stressing the importance of knowing all about the conditions 

 of existence, only to conclude {op. cit., 1851. Pt. 2, (1) p. 241) that 

 "Depuis le commencement du monde anime jusqu'aux derniers 

 etages des terrains tertiaires (sic), on voit . . . une repartition 

 uniforme des etres tout a fait indcpendante des lignes isothermes 

 actuelles, et . . . toujours la faune tropicale" — a paleontological 

 part truth that to some degree still encumbers paleobiogeo- 

 graphical inquiry. 



Neumayr (1883, 1885) subsequently reached a contrary con- 

 clusion from his global analysis of the Jurassic faunas, delineating 

 climatic zones comparable to those of the present day. Although 

 Neumayr's zonation has since been discredited in detail by Uhlig 

 (1911) and Arkell (1956, pp. 615-618), these authors agree that 



