Professor Agassiz on the Classification of Insects. 101 



If this conjecture be true, then, on reaching these bounds, 

 the radiant heat of the world will be totally reflected, and 

 will ultimately be reconcentrated into foci. At each of these 

 foci, the intensity of heat may be expected to be such, that, 

 should a star (being at that period an extinct mass oT inert 

 compounds), in the course of its motions, arrive at that part 

 of space, it will be vaporised and resolved into its elements ; 

 a store of chemical power being thus reproduced at the ex- 

 pense of a corresponding amount of radiant heat 



Thus it appears, that, although, from what we can see of 

 the known world, its condition seems to tend continually 

 towards the equable diffusion, in the form of radiant heat, 

 of all physical energy, the extinction of the stars, and the 

 cessation of all phenomena, yet the world, as now created, 

 may possibly be provided within itself with the means of re- 

 concentrating its physical energies, and renewing its activity 

 and life. 



For aught we know, these opposite processes may go on 

 together, and some of the luminous objects which we see in 

 distant regions of space may be not stars, but foci in the 

 interstellar sether. 



The Classification of Insects from Embryological Data. 

 By Professor Louis Agassiz. 



I. General Considerations. 

 The various classifications of insects which have been 

 proposed by zoologists rest either on considerations derived 

 from their external characters and form, and in part from 

 their internal structure, or on the various modes of their de- 

 velopment from the egg. The earliest writers on classifica- 

 tion availed themselves principally of the number and struc- 

 ture of their wings, to divide the numberless insects into 

 several general divisions, and such an arrangement, as finally 

 adopted by Linnaeus, has prevailed to a great extent, some- 

 times modified by the introduction of some smaller groups, 



