NATURAL SCIENCES OF PHILADELPUIA. 1 / / 



Dr. Leidy stated that a few evenings since, in the yard attached to his resi- 

 dence, he for the first time had the opportunity of observing the male Tree- 

 cricket, Oecanthiis, while chirping. The sound, as is well known, is produced 

 by the insect elevating its wings and vibrating them laterally ; by which move- 

 ment the edge of one wing-cover is rubbed upon a rasp or crepitaculum of the 

 other. The sound is like that of the Field-cricket, Ackela, instead of a peculiar 

 one &3 Dr. L. had supposed it to be. The note he had formerly attributed to 

 the Tree-cricket, and with which the woods are vocal during the nights of this 

 season of the year, is one resembling that produced by the quick and repeated 

 snapping of the end of a quill pen or tooth-pick during a second or two of time. 

 Upon examination Dr. L. found this sound to proceed from the male Katy-did. 

 Platj/p/n/llum ; and the mechanism producing it is similar to the stridulating 

 apparatus of the crickets, Acheta, Oecanthus. 



In the male Katy-did, the crepitaculum, situated on the under surface of the 

 dorsal portion of the wing covers, consists of a transverse, fusiform, concave 

 ridge, provided with about fifty serratures ; and is best developed in the left 

 wing cover. The instrument which rubs against this crepitaculum is the sharp, 

 elevated, inner edge of the dorsal portion of the wing covers, at the side of what 

 might be considered a trilateral tambourine, which is best developed in the 

 right wing cover. The song (if the term may be used) of the male Katy-did ordi- 

 narily is produced by the sharp edge on the inner side of the tambourine of the 

 right wing cover, rubbing against the rasp or crepitaculum of the left wing cover. 



Dr. L. continued, he had always supposed the male Katy-did produced the 

 familiar sound after which the insect is named, and that the female was silent. 

 This he believed was the generally received opinion ; and Dr. Thad. Wm. Harris 

 (Insects Injurious to Vegetation, page 138), remarks that at night " the joyous 

 males begin the tell-tale call." Dr. L. added, after further investigation he was 

 happy to be able to clear the male from the libellous imputation, and that, as 

 was usually the case among our own race, the accusation, recrimination, and 

 denial, of katy-did, katy-didn't, came from the female herself. The apparatus 

 by which the female Katy-did tells her tale is totally different from that of the 

 male, though situated as in this, in the dorsal portion of the wing covers. In 

 the dorsal portion of the right wing cover between the marginal vein, and another 

 about half a line from it, there are about five strong transverse veins and some 

 smaller ones, provided upon their upper surface each with a row of strong 

 spines bent back at right angles. All other portions of the right and the whole 

 of the left wing cover are destitute of such spines. In the left wing cover, the 

 corresponding position to that just described is occupied by a fine rete of veins as 

 elsewhere ; and it is the inner edge of this wing cover rubbing against the hooks 

 of the right one. which produces the tell-tale sound of katy-did, katy-didn't. 



September \st, 1857. 



Vice President Bridges in the Chair. 



Dr. J. A. Meigs read part of a letter from Mr. J. Judson Barclay, 

 dated Philadelphia, Aug. 21, 1857, accompanying the flattened skull 

 presented by him this evening. 



" On referring to my journal, (kept during several years residence in 

 Jerusalem,) I find a brief mention of the circumstances attending the 

 discovery of the very singular skull now in your possession, though I 

 fear it will afford but little aid in assigning any other place of habitation 

 to this unfortunate adventurer, than the subterranean locum tenens of his 

 bones. 



