Record. xxvii 



only one moth was found, although a careful outlook was kept during 

 the middle of the day, the time when the imago is most active. 



An exhibition was made of the larvae at numerous ages, from the 

 emergence from the egg to the time of spinning the cocoon, together 

 with an example of their destructive work on the tree, and numerous 

 mounted examples of the male and female moth of the S. exitiosa 

 type. 



Also a cocoon was shown filled with the larvae of Bracon mellitor 

 (Say), and others filled with the cocoons of this ichneumon, the 

 parasite having been found in from one to two per cent of the S. ex- 

 itiosa cocoons examined. 



Particular stress was laid upon the fact that only black and white 

 drawings of the insects were given in the various state and national 

 bulletins which were distributed throughout the country for the in- 

 struction of the orchardist, and lantern slides were shown from the 

 plates of Beutenmueller in which there were at least 75 other exam- 

 ples of Sesia, which in black and white would readily be confused 

 with this one by the laity. To be of any real value to the people all 

 government bulletins dealing with insects should contain exact col- 

 ored plates of the insects described in order to be Intelligible to those 

 not familiar with entomology. As an example, the owners and the 

 foreman of the Mountainboro orchard did not know the 8. exitiosa 

 until they saw it emerge from the cocoon, although all of them had 

 carefully read all the important government bulletins on the subject, 

 particularly those of Slingerland, Marlatt, and Starnes, and they had 

 owned and cared for the orchard for more than ten years. As the 

 moth flies only in mid-day it was unquestionably often seen by them 

 without being recognized. 



The death of Mr. Samuel Cupples was reported. 



Febkuary 5, 1912. 



President Engler in the chair; attendance 25. 

 Dr. G. O. James addressed the Academy on the sub- 

 ject of "Mechanical Flight." 



Dr. James divided the history of mechanical flight into four peri- 

 ods: the legendary, leading up to the Renaissance; the heroic, ending 

 with the XVIII century; the scientific, extending through the XIX 

 century, and finally the industrial, beginning with the present cen- 

 tury. 



Passing over the first two divisions, the scientific period began in 

 1809, when Sir Geo. Cayley published the first complete mechanical 

 theory of the aeroplane, in which he put clearly in evidence the funda- 

 mental principle of sustention obtained by velocity. This memoir, pub- 

 lished in Nicholson's Journal, passed almost unnoticed until unearthed 

 some sixty years later by Penaud. Following Cayley there was a long 

 period of unfruitfulness. At the close of the Franco-Prussian War 



