Visit to the Diggings. 



6907 



pursuing some bright insect over rocks and bushes, you ran great risk 

 of setting your foot on some deadly snake, or perhaps on a bunch of 

 snakes holding connubial conference. I trod on one most venomous 

 species whilst vaulting over bushes in chase of the beautiful little 

 PoUaclasis viridipulverulenta, one of the Anthroceridae, so like our 

 Procris Statices as always to remind me of that familiar species. 



During the hot weather I observed a dipterous insect with habits 

 so singular that I cannot refrain from relating them. The size 

 was that of one of our largest female bluebottles, but the colour 

 totally different, the Australian species being banded with the 

 brightest golden yellow : often while searching among the scrub, 

 in Launceston Gully, have I seen a pair of these flies " locked 

 in love's embrace," basking in air in the burning rays of the 

 sun. A moment would they seem to rest, poised motionless : they 

 would then rock to and fro, describing the lower half of a circle and 

 returning in the same track, both pairs of wings vibrating in unison 

 and flashing in the sun. On my attempting to net them, ofi* they 

 would dart, still united, but would halt at a very short distance, then 

 hang for a few moments again motionless, and again commence tlieir 

 pendulum-like vibration as before. Although no dipterist I made 

 many attempts to secure this beautiful and unknown fly, and once 

 succeeded in getting a pair into my net, but one of them escaped be- 

 fore I could secure it, and the other alas ! was afterwards accidentally 

 crushed and completely annihilated. 



In December, corresponding to our June, vegetation appeared para- 

 lyzed : trees and shrubs continued to grow, but nowhere is seen that 

 luxuriant vegetation which the fields, woods and hedges of England 

 exhibit during the summer. Australia does not produce that vividly 

 green and succulent vegetation which is so beautiful with us : the 

 vegetation, too, is very monotonous and unvaried. I have wondered 

 how so small a variety of plants can produce so great a variety of in- 

 sects : the larvae, even of the Lepidoptera, feed much in the stems of 

 the grasses and in the bark and wood of trees ; indeed the gum trees, 

 the wattles and a few grasses seem to bear the entire onus of support- 

 ing insect life. I have observed, also, that insects are of less regular 

 appearance than with us. Although at the close of 1853 and begin- 

 ning of 1854 there were thousands of species, they were not nearly so 

 numerous in individuals as twelve months previously, and many spe- 

 cies would be excessively abundant one year that were rare or en- 

 tirely wanting at a corresponding period of the next year. The influx 

 of diggers, the felling of hundreds of thousands of trees, the frequent 



