71 



much the greater number of the iuclividuals perished. Wherever indi- 

 viduals were protected iu the crevices of the wound or under injured 

 bark they persisted over whiter, without exception, though suffering 

 great diminution. Practically no mature individuals persisted over 

 winter. It was also noted that whenever bright days occurred for any 

 )eriod of time in the early winter, so that the mercury ranged from 10° 

 to 50°, where fall-grown females occurred in the winter colonies they 

 gave birth to young. 



The colonies in the greenhouse flourished and continued breeding 

 without hindrance daring the entire winter season. 



In order to note the normal reproduction in this latitude an over- 

 wintered female was taken from the colony on May 5 and colonized upon 

 a potted plant. When taken from the colony she was not full grown, 

 but completed her growth and gave birth to young on the 12th of May. 

 These young were taken as the first generation from the over-wintered 

 agamic female, and on the 30th of May produced young of the second 

 generation. These were likewise colonized for observation and pro- 

 duced the third generation on June 14. Proceeding in like manner, the 

 successive generations were produced on June 29, July 10, July 19, July 

 30, August 7, August 17, August 26, September 7, and September 20, 

 reaching with this date the twelfth generation in a direct line from the 

 over- wintered female colonized in the spring. 



At this date the individuals in our colonies, regardless of their 

 generation, began to become winged, and winged individuals were pro- 

 duced in great abundance, extending over a period of thirty days. The 

 number of the generation had nothing whatever to do with the phe- 

 nomenon of becoming winged. However, a considerable portion of the 

 individuals in our colonies showed no tendency to become winged, 

 and quite invariably immature lice removed from any colony where 

 winged individuals were being produced failed to become winged when 

 colonized upon fresh plants. It would appear that the mere fact of 

 disturbance and removal to a fresh host plant sufficed to arrest the 

 tendency to become winged. 



The winged individuals remained ordinarily at rest in the colony 

 among the un winged lice, but they made no attempt to feed. After 

 several days they would become restless and fly away. Attempts to 

 trace them were in every case fruitless, and we were not able to estab- 

 lish the normal habit of this individual in regard to the production of 

 its young. In no case did we observe them producing young among 

 the individuals of an old colony, and we were unable to locate the young 

 when allowed to breed out of confinement. 



Eetained in confinement, after four or five days they produced their 

 young, usually four to six, within the space of twenty-four hours. These 

 young proved to be sexual individuals and were quite characteristic in 

 their size, organic structure, and coloration. In the first place, they 

 were beakless, having the month parts represented by a triangular, 



