36 



THE LARVA OF THE BLOW-FLY. 



by means of fibres of a tendinous character, which run through 

 the whole thickness of the endostracum (Fig. i, /). 



The Endostracum consists of many laminae, and is more or less 

 distinctly divided into hexagonal columns, several corresponding 

 to each of the cells of the hypoderm. It is perforated by 

 numerous canals, which contain processes from these cells 

 (Fig. I, / and 2) and nerve end-organs, which terminate in 

 the sensory papillae (Fig. i, J, f), immediately beneath the 

 epiostracum. 



Fig. I (bis). — Sections of the skin of the Blow fly larva.— i, a vertical section, show- 

 ing the manner in which the muscles are inserted into the epiostracum ; 2, a similar 

 section, showing the prisms of the endostracum ; 3, a sensory papilla ; 4, a suh- 

 hypodermic cell, with a terminal trachea in its interior, cti. Cuticle ; c, end 

 org.m ; //, hypoderm cells ; i, sub-hypodermic cells ; /, terminal portion of the 

 end organ ; tr, trachea. 



Sensory Papillae. — The surface of the integument, especially 

 near the spiracles and on the anterior edges of the rings, is 

 raised into papillae, which consist of both epi- and endostracum. 

 These papillae contain bundles of fusiform cells, which ter- 

 minate in very fine rod-like organs in the epiostracum at the 

 tip of the papilla, these are the terminal organs of cutaneous 

 nerves (Fig. z., 3,1). 



