CHAPTER VIII. 

 THE ORGANS OF CIRCULATION AND RESPIRATION. 



SPECIAL REFERENCES. 



VERLOREN. Mem. sur la Circulation dans les Insectes. Mem. cour. par TAcad. 

 Roy. de Belgique, Tom. XIX. (1847). [Structure of Circulatory Organs in a number 

 of different Insects.] 



GRABER. Ueb. den Propulsatorischen Apparat der Insekten. Arch. f. rnikr. 

 Anat., Bd. IX. (1872). [Heart and Pericardium.] 



LEYDIG. Larve von Corethra plumicornis. Zeits. f. wiss. Zool., Bd. III. (1852). 

 [Valves in Heart.] 



LAXDOIS, H. Beob. iib. das Blut der Insekten. Zeits. f. wiss. Zool., Bd. XIV. 

 (1864). [Blood of Insects.] 



JAWOBOWSKI. Entw. des Riickengefiisses, &c., bei Chironomus. Sitzb. der k. 

 Akad. der Wiss. "NVien., Bd. LXXX. (1879). [Minute Structure and Development 

 of Heart.] 



LANDOIS, H. , and THELEX. Der Tracheenverscliluss bei den Insekten. Zeits. f. 

 wiss. Zool., Bd. XVII. (1867). [Stigmata.] 



PALMEN. Zur Morphologic des Tracheensystems (1877). [Morphology of Stigmata 

 and Tracheal Gills.] 



MACLEOD. La Structure des Tracheesetla Circulation Peritrachcenne. (Brussels, 

 1880.) 



LUBBOCK. Distribution of Tracheae in Insects. Trans. Linn. Soc. , Vol. XXIII. 

 (1860). 



RATHKE. Untersuch. iib. den Athmungsprozess der Insekten. Schr. d. Phys. Oek. 

 Gesellsch. zu Kiinigsberg. Jahrg. I. (1861). [Experiments and Observations on 

 Insect-respiration.] 



PLATEAU. Rech. Experimentales sur les Mouvements Respiratoires des Insectes. 

 Mem. de 1'Acad. Roy. de Belgique, Tom. XLV. (1884). Preliminary notice in Bull. 

 Acad. Roy. de Belgique, 1882. 



LANGEXDORFF. Studien iib. die Innervation der Athembewegungen. Das 

 Athmungscentrum der Insekten. Arch. f. Anat. u. Phys. (1883). [Respiratory 

 Centres of Insects.] 



Circulation of Insects. 



A VERY long chapter might be written upon the views advanced 

 by different writers as to the circulation of Insects. Malpighi 

 first discovered the heart or dorsal vessel in the young Silk- 



/ o 



worm. His account is tolerably full and remarkably free from 

 mistakes. The heart of the Silkworm, he tells us, extends the 

 whole length of the body, and its pulsations are externally 

 visible in young la^ 7 3e. He supposed that contraction is effected 



