180 APPENDIX. 



repeated experiments of the most able and practised 

 zoologists, so as to place the matter beyond dispute." 

 I by no means, however, mean to assert, that Mr 

 Thompson did not think he saw what he has stated 

 in both cases to take place; but he was probably 

 deceived by appearances, in some such way as he 

 states Sldber to have been. 



A single fact by Poli is sufficient to overturn this 

 whole hypothesis. This illustrious conchologist re- 

 lates that he had an opportunity of examining the 

 immense fecundity of the Sessile Barnacles. " In the 

 beginning of June he found innumerable aggregations 

 of them covering certain boats that had long been 

 stationary, which, when closely examined, were so 

 minute, that single shells were not bigger than the 

 point of a needle j and that from that time they grew 

 very rapidly, and arrived at their full size in Octo- 

 ber." These very minute ones must have been hatched 

 from the eggs, and not produced from larvse. 



NOTE II. (Page 44.) 



" Then there are gnarled trunks of what were once 

 noble forest trees, still clinging with, stony roots to their 

 native soil" There are few subjects more deeply in- 

 teresting than those that bear upon the encroachments 

 of the mighty sea upon the land. For the information 



