THE YOUNG 



pages 7, 60, ami 76. It i.s rather smaller and 

 darker than the common shark. 



firiKPETES PAKTHEXTAS* AND NOTHA.* — The 



Orange Uriderwings fly in the bright sunshine 

 in woods. Parthcnias feeds on birch, notha on 

 aspen, fce., and the imagos may be looked for 

 when these grow freely. Neither species is very 

 common, but they have both been taken in ten 

 or twelve different counties in England -not, so 

 far as we know, in either Scotland or Ireland. 



These conclude our list of newly emerged, 

 species A large number of hibernated insects 

 may be found, among the rarest of which we 

 may name/), rabiginc t*. ats illow, and D. temjili 

 under stones, or at light. Tho>e win take 

 worn Noduce at Sallows, should earjfully pre- 

 serve the females, and they will be very likely 

 to obtain eggs. We should be obligod for a few 

 eggs of any of those species marked thus * . 



Mr. Gregson's paper next week will cover tin 1 

 other species to be met with this month. 



LIFE IN THE EARLY AGES 

 OF THE EARTH. 



Abstract of a lecture delivered at H udders- 

 field, Feb. 25, by Prof. Williamson, President 

 of the Yorkshire Naturalists' Union : being the 

 fourth of a course of Gilchrist Science 

 Lectures. 



The crust of the globe is made up of a series 

 of beds, or strata of rocks, which, if the whole 

 series could be found together at one place, 

 would represent a thickness of about ten miles. 

 Under all this is granite, which, in ail prob- 

 ability, was once in a state of .fluidity, and 

 that fluidity was caused by the intensity of 

 the heat of the mass. If we take anything 

 which is fluid, and cause it to spin round, we 

 find that it not only assumes the shape of a 

 sphere, but one like our globe, rather flattened 

 at the poles ; there is therefore no very strong 

 objection to the theory that this globe was 

 once in a fluid state from intense heat, and 



NATURALIST. 149 



then no life could possibly exist upon it. After 

 a while it began to cool, and when the surface 

 began to cool it began to contract like the 

 rim upon a cart wheel. When it contracted 

 certain points which were weaker than others 

 would give way, and allow the softer interior 

 to be squeezed through it. As soon as it 

 cooled water would begin to settle upon the 

 surface, and as soon as water settled, there 

 would be currents, because the water would 

 not be all of the same temperature, and 

 wherever one portion was hotter than another 

 the hot water would rise to the surface, and 

 the cooler water settle to the lower parts. 

 As soon as currents were set up they would 

 begin to file, or wear down, the surface over 

 which they flowed, and hold the material in 

 suspension, and carry it to some quiet pool, 

 and there deposit it at the bottom, and thus 

 would be formed the first traces of strata. 

 This would go on for millions piled, upon 

 millions of years, until we get the various 

 strata which we find at the present day. In 

 these strata we trace of what the life of by- 

 gone ages were, and my object to-night is to 

 give you some idea of the earlier stages of 

 that life. The first serie; of rocks above the 

 granite is what is known a; the Laurentian 

 rocks, so called became they are best de- 

 veloped about the river St, Laurence, in 

 America, where they attain a thickness of 

 30,000 feet, their con ;truction is chiefly 

 chrystaline, but they contain an object which 

 haj been called Eozoon, which means the 

 dawn of life. Dr. Carpenter and others, who 

 have paid great attention to this object, tell 

 us that it is organic, and it so, and I see no 

 reason to doubt it, it is the first traces of life 

 which we find in the history of the v/orld. 

 Evolutionists teli us that when life first begun 

 it was in a very rudimentary state, and that 

 forms and types kept on multiplying and pro- 

 gressing until we have the vast variety of 

 forms which at present exist, and it is only by 

 turning our attention to the rocks, and ex- 

 amining their organic remains, that we can 

 form any idea as to the truth of these theories. 



