STUDIES OF VARIATION IN INSECTS 



29] 



many variations as remain. This pattern has during all this 

 life or at least during most of it, been as effective as it may be 

 in helping or hindering the individual to successful life. 



Variation in Prothoracic Markings of a Flower-bug. — Three 

 hundred and seventy-eight individuals of a flower-bug (sp. un- 

 determined), collected at one time by sweeping the net over a 

 few rods of alfalfa and Baccharis on the campus of Stanford 

 University were examined for variation in the number and ar- 

 rangement of the spots constituting the pattern of the pronotum. 

 This insect belongs to the family Capsidas, order Hemiptera, 

 and has an incomplete metamorphosis. 



The series of specimens has been grouped in sixteen classes 

 as follows (the spots have been given numbers for the sake of 

 referring to them readily, see diagram, fig. 57). 





P 



k^ \^ vv W 



Fig. 57. Diagram showing variation in pattern of the prothorax of a flower- 

 bug. 



Class A: 2 specimens without spots (fig. 57, a). 

 Class B : 36 specimens with spots i' and i"" present, but small 

 (fig- 57, ^). 



