142 



THE YOUNG NATURALIST. 



Bees which make a nest in the crevice of a 

 wall, or similar site. The nest is com- 

 posed of sand or earth, mixed with a 

 glutinous secretion, or saliva ; cells are 

 formed in it, in each of which an egg is 

 deposited, they are filled with honey, and 

 closed up. The insect when ready to emerge 

 bursts the wall to escape. Of very similar 

 habits are the Carpenter Bees, only, instead 

 of building cells of earth, they hollow out 

 galleries in decaying wood, a work that 

 sometimes occupies a long time. The 

 bottom of the excavation is brought close 

 to the outside of the wood, but not 

 allowed to penetrate it. An egg is then 

 deposited, and a quantity of honey 

 provided. The cell is closed with a cover- 

 ing of wood fibres agglutinated together 

 with saliva. On this another egg is placed, 

 honey provided, and again it is closed in, 

 and this operation is repeated till the 

 gallery is filled. The first laid egg 

 produces the imago first, and it makes its 

 way out. The next penetrates the sawdust 

 bottom of its cell, never the top, and so on 

 until all have escaped by the hole made by 

 the first. The Leaf-cutting Bees line their 

 burrows with pieces cut from the leaves of 

 various trees, which they bend and fix in 

 such a way as to give considerable strength 

 to the structure. All these die before their 

 progeny appear. 



Wasps, like Humble Bees, only live 

 together for the season. They do not 

 secrete wax, but form a substance almost 

 like tough paper. When winter approaches 

 both males and workers die ; only some of 

 the females surviving to formed a new 

 colony in the spring. The workers' eggs 

 are laid first, and till they arrive at 

 maturity she has everything to do herself, 

 but they propagate so quickly that a wasp's 

 nest at the close of a suitable season is 

 reckoned to contain from 3000 to 4000 

 workers, besides males and females. 



Many numbers of the Young Naturalist 

 might be filled with interesting particulars 



of the insects composing this wonderful 

 order, but we must pause here. 



Our next paper will be on Lepidopter \a 

 and the closing one on Diptera. 



A PIECE OF LIMESTONE. 



Abstract of a lecture delivered by Dr. W. 

 B. Carpenter, at Huddersfield, Feb. nth, 

 being the third of a course of Gilchrist 

 Science Lectures. 



The lecturer commenced by stating that 

 most of those present knew what a piece of 

 limestone was, or a piece of chalk, or a 

 piece of marble, but perhaps all would not 

 know that these three substances were 

 I chemically the same, yet how different in 

 j general appearances. A piece of chalk is 

 I generally so soft that it could be taken 

 between the hands and crushed to powder ; 

 marble, on the other hand, is hard and 

 crystaline, and capable of taking a very 

 high polish ; limestone is intermediate 

 between the two, in fact, some kinds of 

 Derbyshire limestone are hard enough to 

 take a polish, and are used for chimney 

 pieces, and are called marbles. The lime- 

 stone and the sandstone or millstone grit 

 forms the basis upon which the coal 

 measures rest, it is called carboneferous 

 limestone, which means coal bearing, 

 because the great coal beds rest upon it. 

 Sometimes the limestone rises up into 

 mountains, as in Derbyshire, and many 

 other places, and we then call it mountain 

 limestone. These three substances, lime- 

 stone, chalk, and marble, are each composed 

 of exactly the same two substances — lime 

 and carbonic acid. This carbonic acid is 

 the gas which animals give off when they 

 breathe, which is formed by the burning 

 1 of gas, which raises dough, and which 

 causes lemonade and drinks of that class to 

 effervess. The way in which these drinks 

 are generally made is from one of these 

 three substances. Get some chalk, and 

 put it into diluted acid of any kind, and 



