209 



Mr. Trego remarked, that some recent excursions into the 

 country in different parts of south-eastern Pennsylvania, and a 

 small portion of New Jersey, near the Delaware, had afforded 

 him an opportunity of making some observations upon the 

 habits of the insect commonly called locust {cicada septende- 

 cem), and as to the extent of the region over which their pre- 

 sent periodical visitation extends. He hoped that from further 

 inquiry, and the observations of others, the boundaries of the 

 region visited by the locusts this year may be approximately 

 ascertained. Among other facts noticed by him, he mentioned 

 that the low sandy grounds along the Delaware and Susque- 

 hanna rivers appeared to be almost entirely exempt from the 

 visits of this insect, while on the neighbouring higher and more 

 clayey or tenacious soils they were abundant. He had ob- 

 served that the twigs of the young chestnut trees appeared to 

 be a favourite place of the female for the deposit of her eggs, 

 but that many other forest and fruit trees were also chosen for 

 this purpose, not, however, so universally as the chestnut. 

 Pines, and other resinous trees, appeared to be nearly or quite 

 exempt from their attacks. 



Prof. Tucker remarked, that he had seen the twigs of the 

 red cedar {juniperus vlrginiana^ affected by the punctures 

 of the female locust. 



Dr. Bridges observed, that a reason why the locust avoids a 

 very sandy soil may probably be found in the fact, that when 

 about to emerge from the earth, the insect forms for its passage 

 a perpendicular cylindrical perforation in the soil, by which it 

 ean ascend and descend at pleasure, until it finally leaves the 

 ground. The inside of this tube is plastered smoothly with 

 clay, which, in a sandy soil, could not readily be effected, and 

 in the loose sand these perforations would not be sufficiently 

 firm or durable for the purposes of the insect. 



Further remarks on the subject were made by Prof. Frazer, 

 Mr. Justice, Dr. B. H. Coates, and others. 



Pending nominations, from No. 256 to No. 261, inclusive, 

 were read. 



