EXPLANATION OF THK PLATES. 559 



Fig. XIV. A piece of the torn membrane, which constitutes the 

 little bladders above mentioned. 



Fig. XV. One of the social vesicular worms, which, collected in- 

 to a family or colony, are situated on the vesicles of figures 

 X, XI, insulated, compressed and viewed, with the micro- 

 scope (no. 6.) — a &, Protuberant wrinkles, which cover two 

 thirds of the body, in a spiral manner.— c rf, Two very mi- 

 nute vesicles, or rather papillae for the purpose of sucking. — 

 e. The crown, with the crotchets elevated on its surface. 



Fig. XVI. Another of the social vesicular worms already demon- 

 strated, enlarged by the microscope (no. 3, tube A,) a little 

 compressed but well distcned. — c 6, Its body covered with an 

 infinite number of small molecules. — c c, Tite tail already fix- 

 ed to the bladder. — (/JrfJ, The four minute vesicles or pa- 

 pillae which suck. — c/, Tlie crown v/ith double crotchets. 



Fig. XVII. A third worm of tiie aforesaid social vesicular fami- 

 ly, attached to their portion of the bladder, and magnified by 

 microscope (no 4, tube A.) — «, Its adhesion to the bladder. 

 —6 6, Its body detached.— -c (/ e. The papillae for sucking, 

 torn.— /, The crown with the crotchets seen on its surface with 

 the tube. 



PLATE THIRD. 



A horizontal section of tlie brain made in order to expose i\\e- 

 two lateral ventricles, in each of which is discovered an as- 

 semblage of human vesicular worms (henniis,) extending along 

 the course of each plexus choroides. — a a a, Circumference of 

 the brain. — A A, The two clusters of worms (one in each lat- 

 eral part) which, coming from the bottom of each ventricle, 

 follow the direction of the two plexus choroides and meet at 

 an acute angle, by means of a particular petiole, in the ante- 

 rior portion of the ventricles. — IJB, The two plexus choroides 

 to which adhere the clusters of human vesicular worms (her- 

 mits.) 



