The Distribution of the Sexes 



mia, did better still : as I have described, she 

 built her nests in my study, as plentifully as 

 I could wish, using reeds, glass tubes and 

 other retreats of my selecting for her galle- 

 ries. 



We will consult this last, who has fur- 

 nished me with documents beyond my fond- 

 est hopes, and begin by asking her of how 

 many eggs her average laying consists. Of 

 the whole heap of colonized tubes in my study, 

 or else out of doors, in the hurdle-reeds and 

 the pan-pipe appliances, the best-filled con- 

 tains fifteen cells, with a free space above the 

 series, a space showing that the laying is 

 ended, for, if the mother had any more eggs 

 available, she would have lodged them in the 

 room which she leaves unoccupied. This 

 string of fifteen appears to be rare; it was the 

 only one that I found. My attempts at in- 

 door rearing, pursued during two years with 

 glass tubes or reeds, taught me that the 

 Three-horned Osniia is not much addicted to 

 long series. As though to decrease the diffi- 

 culties of the coming deliverance, she prefers 

 short galleries, in which only a part of the 

 laying is stacked. We must then follow the 

 same mother in her migrations from one 



los 



