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[No. 1. 



everywhere at the same time. The great eccentricities caused 

 upheavals in different places at different times. Finally, there 

 is an important circumstance which must here be pointed out, 

 and which shows how quietly the oscillations took place under 

 normal conditions. Although, therefore, according to our assump- 

 tion, the radii of the higher latitudes become steadily lengthened, 

 and those of lower latitudes shortened, yet the beach-lines during 

 long geological periods return in the course of the oscillations, 

 in many places, to the former old situation. Thus, A. de Lappa- 

 rent says (Bull. Soc. Geol. de France ser. Ill, vol. XV, p. 400): 

 „J'ai signals, dans le Cotentin, une concordance entre les rivages 

 actuels et ceux ou s'arretait la mer a diverses epoques de Phistorie 

 geologique. J'y ai montre les lignes de rivage se reproduisant, 

 presque sans variations d'altitude, aux epoques hetangienne, 

 sinemurienne, liassienne, cenomanienne, danienne, parisienne, 

 tongrienne, pliocene et actuelle, . . . ., que huit ou neuf fois au 

 moins, depuis Fere primaire, la coincidence des rivages se s'est 

 reproduite sur le meme point;" and at the same place (p. 227) 

 he says: „C'est seulement par dizaines de metres que doivent 

 se compter, dans les parages du Cotentin, les differences entre 

 les nivaux successifs des mers depuis le Trias jusqu'a nos jours." 

 Here we see that the changes in level have taken place with 

 great regularity. The sea has risen and subsequently the land 

 has risen; and these alternating risings have taken place with 

 such regularity that the beach-line, again and again, at long 

 intervals, has returned to its old position. 



It appears from this that there is really a possibility of our 

 hypothesis being sufficient to explain the displacements of the 

 beach-lines that have occurred. We have up to the present 

 considered the relations in the higher latitudes. In the lower 

 latitudes the whole must sink. Here there must be formed 

 „Horste", like what Suess has supposed, and in respect of those 

 regions Lapparents criticism may perhaps not be quite warranted. 

 He has attacked Suestf& doctrine of „Horste" in its entiriety, 

 but has only specially criticized it in regard to such regions 

 (Colorado, the Vosges, the Black Forest, the French Central Plateau) 



