108 THALASSIDROMA BULLOCKII. 



When they move a whelk-pot, the bait sends out oil ; and this frequently 

 attracts Petrels, as fishermen know. 



In ^The Field/ December 14th, 1872, I find in one of my letters on 

 Bullock's Petrel (^Thalassidroma huUocJcii) : — '^At the back of Brunswick 

 Square, Brighton, is a small street in which stands a lamp, under the lamp a 

 gutter, and on Thursday, December 5th, at 8 o'clock p.m., was a puddle. 

 This puddle may reveal to us something about the laws which regulate the 

 zoology of our planet. The lamp shone on the water. As a postman passed, 

 though it rained and blew furiously, he saw a Thalassidroma hullochii alive 

 in the gutter, which he captured and took into a house. On coming out a 

 few minutes after, he observed another fluttering over the same spot, which he 

 also caught, like a butterfly." 



Now, these Petrels discovered the light shining upon the water in a 

 narrow street, and came to it. This gale only began about 4 p.m. on the 

 same day ; yet at 8 p.m. the birds had to run before it. 



It is remarkable that, though my notebook has many examples of 

 T, buHocJcii mentioned in it as taken after gales in Brighton, yet none of the 

 smaller sort (T, pelagicd) ever are. Thus the lesser species is able to ride 

 out the storm, while the larger has to succumb. I have found the same thing 

 here in Swifts and Martins ; the Martins preserve their lives, while the Swifts 

 fail to do so. Yet one would think the stronger and larger bird would have 

 more strength and vitality in the '' struggle for existence." The fact is not so. 



We are, then, not to judge by appearances only in these matters, without 

 actual experience; the "struggle for existence" may be maintained in a 

 way incredible, contrary to our expectations. Take the following instance, 

 which no man would believe unless on proved and reliable evidence. I mean 

 that of the famous snail (^Helix desertorum, Forsk.) in the British Museum, 

 which, as there stated, after having been attached to a tablet for four years 

 in the Museum, was discovered to be still living. It continued to exist two 

 years (from 1850 to 1852) This is marked, ''Egypt: C. Lamb, Esq." 



