ORIGIN OF THE GALAPAGOS ISLANDS 195 



fortunate as to find ourselves surrounded by about fifty of them, 

 which were picked up and brought on board." He also says in 

 this connection that these tortoises can be piled away in the 

 hold of a ship for eighteen months without suffering any 

 diminution in fatness or excellence. It can be seen from this 

 that there is no reason for believing that these tortoises would 

 not be able to remain afloat for weeks or even months without 

 suffering greatly. They always float right-side-up in the water, 

 and if they are inverted immediateh r right themselves as soon 

 as they are released. 



The suggestion of Dr. Stearns 7 that much animal life might 

 have been transported on floating trees, etc., is criticised by 

 Scharff, and the impression is given that the Humboldt is the 

 only oceanic current that bathes the shores of these islands. 

 This is probably true for the southern islands of the group, 

 but not the northern, as they lie within the Panama current 

 and the waters surrounding them are about ten degrees warmer 

 than around the southern islands at the same season of the year, s 

 a fact that is also mentioned by Baur. 9 Pieces of bamboo and 

 cocoanut husks are common constituents of the drift cast up 

 on the shores of the Galapagos Islands. These could hardly 

 be brought hence by the Humboldt current. Such a method 

 of transport is thus possible, but whether or not mollusks, in- 

 sects, etc., would be able to withstand so long a sea voyage I 

 am unable to say. Presumably Dr. Stearns was sufficiently 

 well acquainted with these to speak with confidence in regard 

 to their tenacity of life. 



The question is asked 10 why the agencies of accidental trans- 

 port should have been so much more potent in the distant past 

 than the}* are now. The vascular flora seems to answer this 

 question by showing that these agencies might not have been 

 more potent in the past, and that it is possible that many plants 

 have been brought to the islands within comparatively recent 



7 Mollusk-fauna of the Galapagos Islands, p. 366. 



8 Stewart, I.e., pp.* 226-227. 



9 Baur., I.e., p. 222. 

 10 Scharff, I.e., p. 301. 



THE PLANT WORLD, VOL. 18, NO. 7, 1915 



