70 Transactions of the 



variety of ' scales,' or feathers. Examples of the different 

 forms of these feathers were shown in one of the diagrams. 

 They were arranged on the wings ui great profusion, and 

 generally in a double layer. Mr. Greene next drew attention 

 to the prodigious number of eggs laid by some insects, and 

 to the rapid increase in size of the larvse, or caterpillars. 

 In reference to these points the following extracts will be 

 read with interest : — ' A caterpillar which has been feeding 

 not longer than a month or five weeks will be at least 

 4,000 times larger than when it first emerged from the 

 egg. The caterpillar of the " Goat Moth," which feeds for 

 three years, is 72,000 times heavier than when newly 

 hatched, and the caterpillar of the " Silkworm Moth," which, 

 when born, only weighs the 100th part of a grain, will, in 

 thu'ty days, have consumed 60,000 times its original weight. 

 ... It will be obvious, from what has already been said of 

 their eating powers, that caterpillars must be terribly destruc- 

 tive if their increase be in proportion to their voracity. 

 That this may be so, and often is, will be seen from the 

 following "statistics:" — The female wasp lays 30,000 eggs — 

 the queen bee 50,000 ; a little insect observed by two 

 eminent Trench naturalists produced at the fifth generation 

 — which took place within three months of the first — five 

 thousand nine hundred million individuals, or nearly six 

 times the population of the globe. The female white ant 

 lays her eggs at the rate of 60 per minute, or 3,600 per hour, 

 so that in the short space of twenty- foiir hours she finds 

 herself surrounded by a little family of nearly 90,000 indivi- 

 duals. How long she continues in this prolific mood I am 

 unable to say. But it is among the Aphides that we find the 

 most prodigioiTS multiplication. Professor Owen, an indis- 

 putable authority, has i^roved that a particular species will, 

 in twelve months, produce ten generations, each averaging 

 100 individuals, so that, in the short space of a year, a single 

 parent may see herself the happy mother — if that be the 

 correct term — of a progeny which requires the figure 1 and 

 thii-ty ciphers to represent its numbers.' 



A paper (the first of two upon the same subject) on 

 ' Atmospheric Electricity ' was read by W. J. P. Wood. The 

 first principle laid down was, the attraction and repulsion of 

 electricity to form itself, according as like or unlike kinds 

 are presented to each other. This was illustrated by several 

 experiments. Next, statical induction was treated of, the 

 Ley den jar considered, and the principle applied to the 

 thunder- cloud, the nature of the discharge being explained 

 and experimentally illustrated by the perforation of card. 



