FIRST LECTURE. 7f 



(23) See pi. I. fig. iii. fig. iv. c e. fig. v. C B, 

 and pi. II. fig. i. 



(2^) See pi. I. fig. iii. fig.x. 



(35) See pi. I. fig. xi. and pi. II. fig. i. 



(26) See pi. I. fig. V. 



(27) De la generation des vers dans le corps de 

 Vhomme, etc. T. i. p. 198, S6S. 



(38) Historia naturalis et medica latorum liim- 

 hricorum intra liominem, etc. tab. prima, Jl, B. 



(§9) Opere jisico-mediche T. i. tav. 18. 

 , (30) The work cited, pi. XIX. 



(31) AVe are accustomed to attach to things un- 

 common an idea of singularity which does not ex- 

 ist ; we even forget all delicacy in order to induce 

 belief. It has accordingly been imagined that each 

 joint of a large taenia could live when separated 

 from its contiguous joint. From this idea has orig- 

 inated the name of taenia cucurbitina, by which 

 some have chosen to distinguish one species of the 

 taenia, since it has been thought that this worm 

 was formed by the union of a number of vermes 

 cucurbitinae, or worms resembling gourd seeds. 



This error, which for a long time prevailed in 

 the classification of worms, is now acknowledged 

 to be incorrect, though it has been countenanced by 

 some excellent naturalists. 



If we conrjider that taeniae, like other animals, 

 must gradually obtain their full size, it necessarih 

 follows that their external form must vary with 

 their age : thus a young taenia must differ from a. 

 middle aged tannia. and from one of full ac^e or of 



