Plate LTX 



the hog louse, haematopinus suis linne 



1, Diagrammatic representation of primary and secondary tracheae; 2, stigma, vestibule, bulla, an*^ 

 trachea, drawn from cleared specimen; 3, section through abdominal stignja (a, vestibule; b, lever; c, bulla; 

 d, intrinsic muscle; e, extrinsic muscle); 4, ventral abdominal muscle plate of female, ventral aspect; 5, 

 right lateral abdominal muscles of segment 4 of male (drawn from gross dissection); 6, heart and one-half 

 of length of aorta (a, pericardial cells); 7, transverse section through heart in region of ostium; 8, central 

 nervous system and anterior part of sympathetic system (a, frontal ganglion; b, recurrent nerve; c, brain; 

 d, subesophageal ganglion; e, connectives; f, prothoracic ganglion; g, mesothoracic ganglion; h, metathoracic 

 ganglion and abdominal ganglion; i, visceral nerves); 9, sections through tip of antenna showing multi- 

 nuclear sensory cells (drawn with oil immersion) 



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