182 BRITISH TYROGLYPHID2E. 



Nalepa could not trace. The cells multiply most 

 rapidly at the roots of the long hairs, along the anal 

 opening, and beneath the oil-glands (expulsory vesicles). 

 During this process the cuticula has gradually raised 

 itself away from the underlying soft parts. In the 

 place where the oil-glands lay there are now deep pits 

 in the epidermis. The muscle-bundles situated in the 

 legs and trophi are not lost ; but the large space filled 

 with connective tissue between them diminishes, and 

 the muscles of the various joints blend so as to form 

 an apparently homogeneous cylinder, which is coated 

 by an easily seen epidermis. This cylinder lies in the 

 lumen of the legs without filling it, and after the 

 loosening of the cuticle is still attached to the tip of 

 the tarsus by a fine string. This string soon breaks, 

 and the soft part of each leg draws itself slowly out of 

 the chitinous sheath. The legs then appear as short 

 roundish projections on the surface of the body. If 

 observed closely it will be seen that these projections 

 do not consist of a homogeneous cell-tissue ; but of 

 wholly separate tissue bundles, which must be derived 

 from the muscle-bundles. The muscular tissue has, 

 however, undergone a change, inasmuch as the trans- 

 verse striping has disappeared and the power of 

 imbibition has greatly increased. This softening may 

 also be seen in those muscles which pass directly into 

 the creature in the next stage of its development. 

 Similarly the muscles of the trophi draw themselves 

 out of their chitinous sheaths, and appear as hemi- 

 spherical protuberances from the mouth-opening. 



A large proportion of the body-muscles remain 

 intact ; especially the retractors of the rostrum and the 

 mandibles, the flexors of the coxae, etc. The retractors 

 of the genital suckers and the parts of the leg-muscles 

 which lie within the body become renovated ; and in the 

 change from mature nymph to imago the muscles, 

 especially those of the coxse and the retractors of the 

 mandibles, are strengthened and perhaps partially 

 renovated. 



