The `` Comstock-Needham system '' designed by entomologists John Henry Comstock and George Needham describes these veins and their branches : Crossveins are named based on their relative position to the more prominent longitudinal veins : The hypothetical primitive wing venation pattern is often used as a basis for describing the pattern in modern insects .
The `` Comstock-Needham system '' designed by two entomologists describes these veins and their branches : Crossveins are named based on their relative position to the more prominent longitudinal veins : In extant insects , the term implies a retention of primitive characteristics but not necessarily a simplicity of form .