112 INTERNAL ANATOMY OF INSECTS. 



Two bile-vessels are found in the larva of Cetonia aurata*. 



Four most Coleoptera, Diptera, 



and Hemiptera b . 



Six Lepidoptera, some Coleo- 

 ptera c , &c. 



Eight Myrmeleon, Hemerobius*. 



Fourteen ... Formica rufa e . 



Twenty larva of Clavellaria Ame- 



rince f . 



Many Libellulina,Orthoptera, and 



Hymenoptera s. 



The bile-vessels vary considerably in length : in many 

 cases where they are free they are short h ; they are often 

 very long, and perhaps those that sfejfaed may be gene- 

 rally stated as the longest. In the Lamellicorn beetles 

 they are remarkable for their great length '. 



Having given you this general account of the intesti- 

 nal canal and its parts and appendages, I shall now state 

 some of the peculiarities that in this respect distinguish 

 particular tribes and families. 



The Coleoptera alone, exhibit as many variations in 

 the structure of the alimentary tube as all the other Or- 

 ders of insects together : to particularize these would 

 occupy too large a portion of this letter, I shall therefore 

 only notice a few of the most remarkable. In general 

 they may be stated as having universally a stomach, a 



a Ramdohr, t. vii./. 2. b Ibid. t. ii. iii. &c. t. xx. /. 1, 2. 6. 



t. xxii./. 15. &c. c Ibid. t. xviii./. 1.5.*. iv./. 1. See 



also t. vi.f. 1.3. d Ibid. Anat. t. xvii./. 1, 2. 6. 



"- Ibid, t.xiv.f. 3. f Ibid. t. xiii./. 4. 



Ibid. t. xv. f. 3, 4. t.l.f.1. 5. 9. t. xii./. 4, 5, 6, &c. 



h Ibid. t. xi./. 4. t. xii./. 46. t. xiii./. 24, &c. 



1 Ibid. t. vii./. 1. 1. viii./. 1, &c. 



