378 CHAPTER OF CRITICISM. 



two very fine Walnut-trees, little risings of moisture, like small springs issuing 

 from the Gravel. Between the trees, about twenty feet from each, one much 

 larger than the rest induced me to ascertain the cause, when, on digging down 

 about eighteen inches, I found the bark of the root had given way, and the sap 

 was rapidly oozing out. I counted from the two trees no less than nine springs, 

 some more copious than the others, yet all flowing freely. On Sunday the spots 

 were still very moist, but did not show signs of being on the increase. Can you 

 oblige me, in one of your future numbers, by stating a remedy for this dangerous 

 draining of two fine old useful and ornamental friends ? 



As a constant reader and admirer of your periodical, I take the liberty of 

 forwarding you the preceding communications. Should they be worthy a place 

 in the pages of The Naturalist, I shall feel pleasure in having added a mite to so 

 excellent a Journal. Should they be considered inadmissible, I must request the 

 favour of your pardon, and with all due submission subscribe myself as 



Yours, most respectfully, 



Stoke Ferry, Norfolk, Richakd Pigott. 



May 14, 1838. 



[^The eruption alluded to as observed in the trunks and roots of the Walnut- 

 trees, probably arises from a disease scarcely to be subdued by local applications, 

 a method, however, which would be as well tried, since no harm could ensue. 

 An adhesive fluid or plaister might answer the purpose, but it is impossible to 

 supply definite information on this head without inspecting the invalids. We 

 should be glad to learn the experience of any correspondent in the matter. — For 

 the above interesting communications we beg to return thanks, and to express a 

 hope that Mr. Pigott will become a frequent contributor to the pages of The 

 Naturalist. — Ed.]] 



CHAPTER OF CRITICISM. 



On the Formation of Pearl. 



To the Editor of the Naturalist. 



Doncaster, May 17, 1838. 



Dear Sir, — At the conclusion of a very interesting lecture by Mr. Edwin 

 Lankester, at our Lyceum, the chairman, Mr. Morey, complimented him on 

 its originality, and in particular for the novelty and importance of his remarks 



