Diaspince. 33 



rim and a central tongue or bulbous process. The tubes, having 

 thin chitinous walls, remain visible in the skeletonised preparation, 

 but the essential parts of the organ — the silk glands and their 

 delicate ducts — are destroyed with the soft parts of the body. Dr- 

 Antonio Berlese, in his most excellent paper referred to above, 

 shows that the silk glands communicate by long delicate ducts 

 with the capitate extremities of the tubular spinnerets. I take the 

 liberty of copying one of his figures representing a spinneret with 

 its glands {fig. 15). Some of the tubular spinnerets open on to 

 the dorsal surface or the extreme margin by conspicuous oval or 

 semilunar pores, others communicate with the squames, which are 

 minutely perforate at their distal extremity. 



The ovaries occupy the greater part of the body after gestation, 

 extending even to the anterior margin, so that the whole insect 

 sometimes appears to be tightly packed with the embryos. 



For a description of the muscular and nervous systems I must 

 again refer the student to Dr. Berlese's exhaustive work and 

 admirable figures, in which the physiology of the insect is most 

 minutely treated. 



The first larval stage of the male insect is indistinguishable 

 from that of the female, and the second does not greatly differ in 

 the two sexes so far as the insects themselves are concerned, 

 though the characters of the puparia diverge during this period. 

 The male of the second stage is perhaps rather more oblong than 

 the female at the same period. It is without limbs, the rostral 

 apparatus is present, and the terminal segment is in the form of 

 a pygidium, fringed with lobes and squames and provided with 

 tubular spinnerets. Towards the end of this stage the future ocelli 

 become apparent as dark diffused spots on each side of the head. 

 The dorsal parts do not become indurated at the time of the 

 second moult, but the thin skin is pushed off backwards, revealing 

 the pupa (//. II. fig. i). 



In this third stage the male insect has lost all likeness to the 

 female. The mouth-parts have entirely disappeared, the limbs, 

 antennae, and wings are present in a rudimentary form, enclosed 

 in their pupal sheaths, but lying free from the body. The divisions 

 of the thorax and abdomen are more distinct. The extremity of 

 the body is at first simply rounded, but subsequently a conical 

 spike is developed which contains the genital sheath. The rudi- 

 mentary limbs also increase in size during this period. 



The adult male, after shedding the pupal skin, remains for 



F 



