REPORT OF H. G. lIljniJARD. 
As the moths live and continue to lay eggs tor many days, it follows that the sue- 
cessive generations rapidly become intermingled ami contused. Any division into 
exact periods is therefore hypothetical, but the maximum number of generations can 
be arrived ;it with certainty by combined observations in the Held and in vivaria. 
The following statement exhibits in tabular form the conditions observed in the 
field, together with the periods of" time occupied in each stage of growth, as deter- 
mined by numerous experiments made from time to time iu vivaria indoors and under 
nettings iu the lield : 
