Note 210 — LETTER XXXVIII.
Reading edition
De Geer vi. 67. t. iii. f. 10. ss. 14. Mr. W. S. MacLeay (Philos. Mag. N. Ser. No. 9. 178.) says that in this grub the longitudinal trunks of the Tracheæ send off at equal distances lateral branches just as if there were spiracula to correspond with them. This is evidently a preparatory step to the formation of those that ultimately appear in the perfect insect.