FIRST LECTURE. 89 



(148) Pallas, JSTeue nordiscJWf Seytrage ijBanA 

 if sriick, p. 3, no. 21. 



(149) Leske, Elementi di storm nat. parte prU 

 ma, vol. ii. p. 231, no. 3. 



(150) Tricoceplialos qt capillary head. 



(151) This worm constitutes the seventh ge- 

 nus of Block, Traite de la gen. etc. p. 7~> and the 

 second genus of Goeze, in the ivork cited, p. 113. 

 The former speaks of one species only, that is — of 

 the human; the second describes a tricocephaius 

 with the simple head (others reckon three species of 

 them besides the human,) and one other having 

 the head with fangs, see % XXXIV. 



(153) I say more frequently, because Bloch 

 has sometimes found it extended in a spiral line ia 

 the human coeciun, as may be seen in his work al- 

 ready quoted, pi. IX, fig. viii. The form of this 

 worm is very clearly represented in pi. IV. fig. i, ii. 



(153) See pi. IV, fig. iii. 1 ra. 



(154) Satura observationum de animalcalis in- 

 fasoriis, Goftingue, 1765, 8°, p. 6. 



(155) Commentaria PetropoUt. etc. vol. xix, 

 p. 449. 



(156) In the i2th part of his JWtur forscher, 

 p. 183. 



(157) Versuch. JSTatiirg. etc. p. 115. 



(158) See pi. IV. fig. iii, a. 



(159) Vermiiim intestin. etc. p. 85, 



(160) See pi. IV, and compare it with fig. i. 



and ii. 



IS 



