16 



interesting objects ; so also is the mouth proper, with its 

 masticating apparatus in the case of the coleoptera and larvje, 

 but which in the lepidopterous imago is modified into a suctorial 

 organ. The compound eyes are most beautiful and elaborate, 

 consisting of innumerable facets or lenses, radiating from a 

 centre. When a section of the eye is cut, it is seen that 

 these lenses are somewhat cone-shaped, the apex of the cone, 

 which is covered with a black pigment, being, of course, 

 inwards. One little spot in the centre of the apex is left 

 uncovered, through which passes a filament of the optic nerve 

 situated at the back of the eye. Then again there are the 

 antennae to be worked at ; and a very large field for study 

 they afford, as their use has not been thoroughly and clearly 

 made out. The internal organs of insects will also afford 

 unlimited amusement and instruction ; but to observe them 

 properly it will be necessary to dissect them out carefully. 

 This is generally done in a shallow trough of water ; the parts 

 are teazed out with needles, or dissecting knives, the water 

 enabling the parts to separate more easily. 



I will not weary you with a lengthy paper on Microscopy, 

 but, before concluding, will just consider what Entomology 

 has done for us. In the first place it has enabled us to dis- 

 tinguish some of our friends from our foes ; and a knowledge 

 of their life history enables us to cope with them. I am afraid 

 our enemies rather outnumber our friends, but it may be that 

 we have not yet learned to make use of them. 



The cockroach has for years, and is still by some, considered 

 to be an enemy ; but lately the medical profession has brought 

 his ground-up body into use as a medicine, thus turning him 

 into a friend. Again, he is said to be a very assiduous hunter 

 after the bed-bug, which he devours ravenously. Were it not 

 for the blow-flies, burying-beetles, and others, foul matter 

 would be left to putrefy, and pollute the atmosphere, and en- 

 gender disease, therefore we may classify them as friends, 

 although they are sometimes a source of annoyance. 



What better friends have we in the insect world th^^n the 

 honey bee, the silkworm, and lac-coccus, which produces not 



