CERTAIN TAXONOMIC CHARACTERS OF GRYLLUS. 9 



smaller size. The normality extends even to the venation, as can be 

 seen by reference to fig. 1. The slightly different shape merely means 

 that the length is reduced more rapidly than the breadth. I am not 

 certain that objection could not very properly be made to an attempt to 

 class them in the category of "vestigial" wings. They might more 

 properly be called "reduced." We would then have three classes of 

 wings among adult insects -vestigial,* reduced, and normal. Possibly 

 a fourth class, " hypertrophied, " may exist, but I can recall no example 

 of it. I would define that wing as "normal" which is just sufficient for 

 the function of flight. A "reduced" wing is one which is normal in all 

 respects except size, but which is too small for flying purposes. "Ves- 

 tigial" wings are not only small, but present abnormalities of structure. 



Fir;. 1. Long and short wings of <-Jr//?lnn. Drawn to the same scale. 



I think Burr's (1899) paper is an instance of the confusion which 

 results from a failure to keep these distinctions clearly in mind. He 

 states that in Orthoptera "as the female is larger and heavier than 

 the male, it is in the female that the abbreviation occurs more fre- 

 quently." The data given in table 11 do not support this idea, when 

 applied to reduced wings of Gryllus. However, not only among Orthop- 

 tera, but among insects in general, the female is more apt to have ves- 

 tigial wings of Brues's type 1 than the male. Another statement in the 

 same paper by Burr does not hold when applied to the wings of Gryllus. 

 He says: "As the female increases in size, so the elytra and wings 

 diminish, varying in inverse ratio with the magnitude of the creature." 

 This would amount to a negative coefficient of correlation, and I have 

 found none such, either when studying local collections or when con- 



*Brues seems justified in dropping the term "rudimentary" in this connection. 

 Unless it can be proven that we have adult insects with poorly developed wings 

 whose ancestors never had any better, we can not speak of the poorly developed 

 wings of these adult insects as being "rudimentary." They are either "vestigial" 

 or merely "reduced." 



