19+ [Aug. 



(le VVied, accompanying the copy of Dr. Riippcll's work on the Fauna 

 of Abyssinia, announced at last ineetinu;. 



On motion, it was Resolved, That the Puhlication Cominittoe hp 

 authorized to present to the Prince de Wied, Part 2, Vol. VIII., First 

 Series, and Parts 1, 2 and 3, New Series, of the Journal of the Academy. 



August 21 st. 



Dr. Bridges in the Chair. 



The following letter from Miss M. H. Morris, of Germantown, dated 

 July 21st, 184'9, was read by the Corresponding Secretary. 



" I have delayed proposing a name for the Cecidomyia, that feeds in the culm of 

 the wheat, because I wished my communication to be accompanied by a complete 

 series of specimens Irom the eg^ to the perfect fly; but since 1843, it has not 

 appeared in this neighborhood in sufficient numbers for me to trace it through 

 its several changes : I am therefore obliged to offer the name of C. culmieola, 

 Q3 an appropriate one, with a brief history of its habits, as I have eeen it, and 

 trust I may be more fortunate in future in procuring specimens for exami- 

 nation and description. 



The insect deposits its eggs early in June, on the grain, in or over the germ, 

 while the grain is in the soft or milky state. The eggs remain unhatched until 

 the grain germinates, but when the plant has grown about three or four inches, 

 the worm may be seen, with the aid of a strong magnifying glass, feeding above 

 the top joint, in the centre of the culm, where it remains until it has arrived at 

 maturity. Should this occur before the culm has become hard, the worm eats its 

 way through the joints, inside of the straw, and makes its escape at the root, 

 ascends the straw on the outside, where it attaches itself firmly, and awaits its 

 change; the outer skin becomes the puparium. In the pupa, or tlax-seed state, 

 it closely resembles the C. destructor, and has heretofore been mistaken for that 

 species. 



Should the culm of the wheat become prematurely hard before the worm has 

 finished feeding, as is often the case, the insect will remain imprisoned for life, 

 passing through its changes inside the straw, and there perish without the power 

 to escape, ualoss some accidental passage be made for it. I have liberated hun- 

 dreds with my pen knife, and thousands make their escape after the grain has 

 been reaped and carried into the barn. 



When the insect is thus unnaturally retarded, the time of its perfect develop- 

 ment is uncertain; and I have found them on the straw, and in spiders webs, in 

 and near a barn, from June until September. This destructive insect may there- 

 fore be carried in the straw from one country to another, as well as in the grain." 



Letters were also read : 



From the Secretary of the Royal Academy of Sciences, of Brussels, 

 accompanying the donation of the numbers of the Bulletin of that So- 

 ciety, annoimced this evening, and soliciting an exchange of publica- 

 tions, which was accordingly ordered. 



From ISI. Lacordaire, dated Liege, April 20, 1S4-9, returning ac- 

 knowledgments for his election as a Corresponding Member, announc- 

 ing the receipt of the Proceedings of the Academy presented to him 



