216 



TEXT-BOOK OF ENTOMOLOGY 



and bees, C. Janet states that each consists of a group of fibres 

 diverging from a tendon, which is an integumentary invagination 

 (Fig. 236). Each fibre may be regarded as a multinucleate cell ; 



ht 



FIG. 284. Section through the prothorax of Diapheromera femora-turn: prov, proventriculus ; 

 tr, trachea; n. c, nervous cord; s. gl, salivary gland; hyp, hypodermis ; w. 1, urinary tube; 

 M, heart ; m, m,", m'", muscles for lowering and raising the tergum ; m', another muscle, its use 

 unknown. 



D 



ViSALtr t ^-J 



Fro. 235. Striated muscular fibre of Hydrophilus : A and A', two liini; 1 .. in a -Mir ut' c\tni- 

 sion : <(. tliick disk ; ?/. thin disk ; c, intermediate space. C, />, portion of the same lihrilhi 

 moving the objective farther away and usiiif,' :i siniill diaphragm ; n, thick ; c, tliin disk, x 2000 

 Uiain. After Kanvier, from Perrier. after Gehuchten, from Lang. 



