Diagram of tracheal system of insects for glossary entry. From Kellogg (1). Original caption:
Left (original Fig. 34.) Diagram of tracheal system in body of beetle, sp. = spiracles; tr. = tracheae. (After Kolbe.)
Center (original Fig. 35.) Diagram showing main tracheae in respiratory system of locust, Dissosteira carolina. (After Snodgrass)
Right (original Fig. 36.) Diagram showing respiratory system in thrips. st. = spiracles. (After Uzel, much enlarged)