192 THE EMBRYOLOGY OF THE HONEY BEE 



lying close to the inner surface of the hypodermis and consisting 

 of but three or four fibres, which take their origin on the hypo- 

 dermis a short distance below the stigmata, on the ventral side 

 of which they are inserted. These muscles are so insignificant 

 that they are easily overlooked except in favorable tangential 

 sections. 



The muscles of the alimentary canal comprise a well defined 

 layer of minute circular fibres enwrapping the whole alimentary 

 tract, including the fore- and hind-intestines, in addition to which 

 is a layer of longitudinal fibres, much fewer in number and more 

 scattered than those of the circular fibres (Fig. 74 MclEnt). 



MclEnt — 



Fig. 74. Part of a sagittal section through the dorsal wall of the mid- 

 intestine of a newly hatched larva (Stage XV), showing the muscular 

 coat {MclEnt), x 600. 



These muscles, both longitudinal and circular, may conveniently 

 be termed the enteric muscles. They are best developed in the 

 fore-intestine, and here the longitudinal underlie the circular 

 fibres. In the case of the mid-intestine this relation, as in the 

 imago, is reversed, the longitudinal fibres lying outside the 

 circular. This is also true of the hind-intestine. The fibres mak- 

 ing up the enteric muscles are extremely delicate, and the muscle 

 nuclei minute. On the mid-intestine the circular muscle 

 fibres are fairly numerous and regularly arranged, the longitu- 

 dinal fibres, on the contrary, are scattered and of such extreme 

 delicacy that it is only in favorable cases that they can be seen 

 at all (Fig. 74). Muscle fibres also run from the anterior (dor- 

 sal) wall of the labrum to the anterior (dorsal) wall of the 



