AT THE MICROSCOPE. S9 



cabbage and broccoli, and their allies. Here, though not occurring 

 in "countless thousands " (a serious exaggeration), it may frequently 

 be met with in sufficient plenty to furnish materials for microscopic 

 examination. The female seems never to move from her place, 

 when engaged in the act of oviposition, till she has " had out her 

 lay," as henwives call it when speaking of fowls. Hence the eggs, 

 usually from 12 to 20 in number, are placed on the arc of a circle, 

 in describing which the end of the abdomen would be the pointer; 

 they (the eggs) are of a long oval in shape, and shortly stiptate ; the 

 young, when hatched, disperse to different distances along the leaf 

 on its under side ; they have a short and simple J>romusa's, which is 

 deeply plunged into the tissues. They exuviate several times, 

 moving further apart on each occasion. A delicate fringe of waxy 

 rods is formed by exudation from openings placed around the 

 margin of the flattened scale-like body : these doubtless serve as a 

 protection from parasites, which are probably acarine. Both larvae 

 and pupae have the strongest resemblance to Coccus. At maturity 

 the imago breaks through the anterior part, leaving the pupa skin 

 behind, still attached to the leaf It is a most beautiful and inter- 

 esting creature, which might be said to be a Coccus in its early 

 stages, and (but for its mouth) a Lepidopteron at maturity. In this 

 connection it may be specially noted that the feet of the adult in- 

 sect conform to the Lepidopterous, and not to the Homopterous 

 type. 



The perfect insect may, as to its general aspect, be fairly 

 displayed by killing on a slide, with the gentlest pressure, as a thin 

 covering glass, and mounting dry. The exuvia of the pupae also 

 show well in the dry state. Dissections must be mounted in shallow 

 cells, in fluid, and also the eggs and the larval condition. These 

 latter may be detached from their connection with the leaf, with- 

 out injury, by means of a dissecting knife, such as may easily be 

 made out of a tailor's needle, stuck into a handle and ground flat 

 towards the point, on a hone. With a watchmaker's eye-glass pass 

 this carefully underneath for a little distance towards one end, lift 

 gently, and then remove the insect with a fine sable pencil. 



ThripS' (Plate 8. lower half)— Examples of this insect may 

 be obtained in abundance at the present time (July). They especi- 

 ally haunt flowers; those of the Great Hedge Bindweed ( Coiivol- 

 vuhis sepium)^ of the Vegetable Marrow, or Datura stramonium^ 

 win yield many specimens ; three examples have flown on to my 

 book lately whilst reading in the shade these blazing days. They 

 are easily preserved by taking up with the wetted end of a finger, 

 transferring to a slide on which a drop of glycerine has been placed, 

 and cementing the covering-glass with gum dammar in benzole. 



