92 



ANIMAL PHYSIOLOGY. 



[LESSON 27. 



the hair, except in the attenuated portions, but to show the great dis- 

 parity of size in the terminal enlargement, a figure of it (Fig. 157) is 

 also given. 



463. An exceedingly interesting and beautiful hair is obtained 

 from a species of Bat, common in India, the scientific name of which 

 is not known, although the hairs have been found in the cabinets of 

 microscopists for fully twenty years. The imbrications are arranged 

 as a whorl (Fig. 158) which surround the shaft. It is altogether un- 

 like the hair of any other known species. 



464. But it is reserved for still lower animals to show what ex- 

 traordinary weapons hairs may become ; in a Marine worm (Aphro- 

 dita hispida) the hairs are transformed into darts, and used as such 

 (Fig. 159). The specimen from which the drawing was made, was 

 dissected from the body of a naked (without a shell) Sea-slug Ap- 

 lysia in whose integument a number of them were found It will 



FIG. 159. FIG. 160. FIG. 161. 



Hair of Aphrodita 

 hispida. 



Hair, larva of Der- 

 mestes lardariua. 



Hair, larva of Dermestes, (more 

 magnified). 



be evident that, once in, there they must remain, as, from their struc- 

 ture, no power could extricate them, and consequently they were 

 broken off, that the Sea-mouse (as these Annellides are called) might 

 escape ; but, is it possible to imagine a better shaped harpoon ? 



