540 



THE INVERTEBRATA 



which work the two chitinous stylets; a suctorial pharynx, the wall 

 of which is composed of radiating muscular fibres, follows. Into the 

 pharynx opens a pair of salivary glands. The animals pierce the wall 

 of plant cells with the stylets and suck the sap by the action of the 

 pharynx. Then comes a narrow oesophagus leading into a capacious 

 stomach, and lastly the rectum, which is joined by two short tubes 

 which probably represent Malpighian tubules, and by the duct of 

 the gonad. 



Fig. 370. A, A/jym/)/ion, an example of the Pantopoda. After Mobius. ^6. pro- 

 boscis with mouth; chc. chelicera; pp. pedipalp; ol. ovigerous leg; i, 2, 3, 

 first three ambulatory legs ; ops. opisthosoma bearing, 4, last pair of ambu- 

 latory legs. Fusion of first four segments indicated by stippling. B, Macro- 

 biotus, ?, dorsal view. Modified from Greeff. cl. cloaca; cor. corpuscles in 

 body cavity; gl. dorsal accessory gland; M. mouth; m.t. Malpighian tubule; 

 od. oviduct; oe. oesophagus; o. ovary; ph. suctorial pharynx; sa.gl. salivary 

 glands ; st. stomach ; sty. stylets. 



The perivisceral cavity contains no connective tissue cells but is 

 crowded with numerous rounded corpuscles and traversed by bands 

 of longitudinal muscle. The nature of the cavity is not known but 

 the existing account of the embryology describes pairs of coelomic 

 pouches arising as outgrowths of the archenteron, as in the echino- 

 derms. 



