280 American Association. 



very narrow prolongation of the present galf of St. Lawrence. 



The conditions of cliniate, ice, drift, &c., corresponding to these 

 different shores must have been very diverse." 



Again, in the stratified drift, it is possible to recognise, within a 

 few inches of each other, a bed containing deep-sea shells, and 

 another containing species that are littoral ; these sea bottoms 

 corresponding to different levels of the land. It is evident that 

 any conclusions with reference to the climate indicated by the 

 marine fauna of these successive beds of marine detritus, must 

 take into account these fluctuations of the sea level, and the 

 changes in animal life consequent on them. Taking these into 

 account, positive and reliable results may be attained ; and the 

 study of such districts as the St. Lawrence valley may be made 

 to contribute toward the elucidation of the conditions of life in 

 older formations." 



NORTH AMERICAN LAKES. 



The fluctuations of level of the American lakes, have often 

 formed a subject of inquiry and speculation. They were brought 

 before the Association by Mr. Whittlesey. "These fluctuations 

 presented three distinct features. There was first the general rise 

 and fall, extending through a long period of time ; then the annual 

 rise and fall which occurs regularly within a certain period of each, 

 yeai', and which he styled the annual fluctuation ; then there was, 

 the third, a local, fitful, and irregular oscillation, lasting sometirnes 

 from three to five minutes, and varying in duration from one tp 

 twenty-four hours. He had no difficulty in explaining the general 

 rise and fall of the lakes, as they were merely the reservoirs for 

 the di'ainage of the country of the surplus water, which passes 

 thence by the St. Lawrence as a general opening to the sea. Mr. 

 Whittlesey rea^ a variety of statistics in reference to the range 

 and extent of the two first mimed fluctuations, and said he was 

 unable to find in these, or in the examinations he had made, any 

 confirmation of the popular behef that there is a seven years rise 

 and fall of water in the Lakes. He then directed attention to 

 cause of the third phenomenon — the irregular fluctuations which 

 occur without any particular known cause. Although these pulsa- 

 tions, as they might be termed, were the first to attract notice, they 

 were the last to have received any attention. They occur in all 

 conditions of the atmosphere, but whether produced by electro- 

 magnetic influence or not he could not say, although he thought 

 it not unphilosophic to look in that direction for their cause." 



