SOME BIRD NOTES 277 



true species, but the young of the pilchard, except where 

 dishonesty steps in and sprats are manufactured into * sar- 

 dines.' 



" Finally, not being on the spot, I will not be dogmatic 

 enough to say what I believe to have been the cause of these 

 variations in the usually methodical movements of both 

 smelts and sprats. I have an opinion ; and in the many 

 years I have delighted to study fishes (and other creatures) 

 and their ways, I have always found that effects were pre- 

 ceded by definite causes (except in the case of a man driving 

 a wheelbarrow). But the causes affecting the fishes in ques- 

 tion were such as are wholly unpreventable by man. Per- 

 haps some one will venture an opinion before I presume to 

 suggest my own. "Yours truly, JOHN KNOWLITTLE. 



"GREAT YARMOUTH." 



On December 1st I received the following interesting letter 

 from an old naturalist friend. He wrote : 



" OULTON BROAD, November 29^/2, 1906. 



" DEAR MR. PATTERSON, 



" I know nothing about sprats and less [about] her- 

 rings, but an experienced fisherman told me a month or so 

 ago that they would not get the big shoals of herrings in 

 until the temperature of the sea fell to 32 deg. I believe 

 that the sea temperature during the last two months has 

 been abnormally high, and I know that it did not fall to 

 49 deg. in Lowestoft Harbour until last Sunday. 



" Now if you confer with . . . our engineer at the Ice 

 Factory, South Quay, they can show you a record of sea 

 temperatures which, I believe, they have kept since we 

 started ice-making. I make this suggestion to you because 

 I believe the periodical migration of fish is more ruled by 

 the temperature of the water than anything else, and that 

 some of the, at present, unsolved problems on this question 

 will be materially forwarded by records of the variation of 

 sea temperatures, which partly answers the question asked in 

 the Daily Press. 



" The Baltic emptying its waters, and the Gulf Stream 

 striking the land near Bergen, make that the most rainy 

 place in Europe, and these waters forming uncertain eddies 

 of hot and cold, I fancy account to a great extent to the un- 

 certain migration of fishes and to their habits also. . . . 



" Yours truly, W. S. E." 



And on December I5th, 1906, referring to the proposed 



