2S 



HARDWICKE'S SCIENCE-GOSSIP. 



to him between the points of a pair of scissors. He 

 evidently esteemed the first named as a veritable 

 bonne bouche, and showed his preference and thorough 

 appreciation of it by vulgarly, but very demonstra- 

 tively, licking his wide mouth (furnished with two 

 rows of teeth) well after each piece. 



Feeding him in the above-mentioned manner tried 

 my patience sorely, for, as I have before stated, he was 

 a slow feeder ; but I was stimulated into perseverance 

 by the hope that providing living insect food for him 

 would not again be necessary. But my pet was a 

 knowing little fellow, always on the alert, and the 

 instant he heard the buzz of a fly and saw it on the 

 wing, he persistently refused the proffered meat, and 

 there was nothing for it but to box flies and other 

 small insects alive, and tumble the box, which opened 

 as it fell, near him, and let free the poor victims. At 

 first Tommy was startled, and would run and hide 

 when a box rolled near him ; but he soon learned 

 to know what it contained, and would eye quite ex- 

 pectantly any person approaching him, box in hand, 

 and would be ready to seize his prey the instant it 

 escaped. 



Tommy never took much water during the summer, 

 or when he was in good condition. It was only on 

 the occasion of his reappearing in the winter, as I have 

 previously mentioned, when his body was attenuated, 

 and his skin dry and hanging in folds around him, that 

 water appeared useful and grateful to him. Weak, and 

 scarcely able to drag himself along, yet he would 

 immediately make for it ; at first stand with his 

 anterior limbs in it, and drink by slow but continued 

 lapping for quite half-an-hour, after which he would 

 wade into it, and remain for some time with the 

 posterior portion of his body resting in it. This 

 appeared a strange proceeding, considering how 

 sensitive the lizard is to cold ; but after mature con- 

 sideration, I judged it must have been for the purpose 

 of cleansing the pores, a row of which runs down the 

 inside of each thigh of the Z. vivipara. 



(To be continued.) 



TEETH OF FLIES. 



By W. H. Harris. 



No. 12.—CORDYLURA PUB ERA. 



THE fly whose dental organs are represented in 

 the present illustration belongs to the Acalypte- 

 ratse division of the Muscidse ; it is by no means rare 

 if sought for in its usual habitat ; it frequents marshy 

 places, banks of rivers, and sluggish streams. 



In size and shape it approaches very nearly the 

 common dung-fly, but there are points of difference 

 which distinguish it very clearly from Scatophaga 

 stercoraria. 



The following description is taken from Walker's 

 * Insecta Britannica.' "Head and thorax with 



white tomentum ; palpi tawny, with darker tips ; 

 antennae not near reaching the epistoma ; third joint 

 longer than the second. Thorax with two broad 

 black stripes. Wings grey, tinged with yellow in 

 front, tips brown, a slight incision at the tip of the 

 prasbrachial vein ; discal transverse vein parted by 

 much more than its length from the praebrachial 

 transverse vein, and by much less than its length 

 from the border, haltiers, tibiae, and tarsi tawny ; 

 abdomen slightly tinged with grey. Male : front 

 very broad, frontalia deep black. Female : front 

 moderately broad, frontalia red, abdomen compressed 

 at tip." 



The proboscis of this fly is of the ordinary type 

 possessed by the Muscidae, each lobe contains seven 

 teeth of universal form, they are simple stiletto- 

 shaped organs, long, and moderately stout, hard and 



Fig. 9. — Cordylura pulcra. 



brittle, breaking with a clean fracture if unduly 

 pressed, they are deep amber in colour, and collec- 

 tively occupy a large portion of the oral aperture. 



This appears to be the most primitive form of 

 tooth, they are met with in many species of the Mus- 

 cidae, in varying size and number, rarely, however, do 

 they attain any great size, but range from hair-like 

 processes to short blunted rods ; it is in this fly the 

 greatest development has been found, and hence it is 

 made the type. The various forms of teeth appear to 

 be produced by a simple process of evolution. At- 

 tention has been directed from time to time to the 

 folding of the membrane which forms the foundation 

 for the chitinous deposit, sometimes this folding 

 commences at the base and terminates before reaching 

 the free end, at others this order is reversed ; oc- 

 casionally the membrane is considerably more con- 

 voluted ; it is to the modification of this process wc 

 must look for the origin of form, by the diminution or 



