372 KANSAS ACADEMY OF SCIENCE. 



more than hypothetical, since many constellations, such as Orion, still 

 have wisps of nebulse trailing after the principal stars, as if they were 

 not yet the finished products of creative efforts. Most of the well- 

 known constellations, too, show other evidences of close relationship 

 — common spectral lines and similar proper motion. Most of the 

 star clusters have unresolved nebulous masses within them. The 

 six bright stars lying in an empty space in the heart of the great 

 nebula of Orion, like diamond eggs in a world-nest, strongly suggest 

 their origin from that nebula. Recent photographs show that the 

 normal shape of nebulous masses is spiral, as if under the influence 

 of tangential and gravitational forces. This may lead to a modifica- 

 tion of La Place's hypothesis, whereby attendant stars and planets 

 arise from masses switched off from such rotating nebulae, instead of 

 collecting first in the form of rings like those of Saturn. If this be 

 true, this planet and such annular nebulae as that in Lyra are anoma- 

 lies. It is suspected also that the galaxy conforms to the prevailing 

 spiral type. Some nebulae show but very few spectral lines, as if 

 made up of those elements only. If there is an identity in structure 

 and nature throughout the universe, all the elements, or most of them, 

 ought to show in the spectrum. This has given rise to the theory 

 that these masses are truly embryonic, most of the elements being as 

 yet undifferentiated. Professor Haeckel believes that matter arises 

 from condensations of ether, hydrogen being the simplest sensible 

 matter, or perhaps a hypothetical substance he calls prothyl. From 

 differentiations of this all the other elements arise. Other astrono- 

 mers think that the reason only two or three elements appear in the 

 spectrum is that the lightest gases are thrown out to the periphery of 

 the masses by whatever forces generated the nebulae, but that after a 

 time these settle so as to reveal the heavier substances. In any case, 

 we are witnessing the processes of world-formation in nebulas. 



Perhaps you will pardon, in closing, the mention of a curious hy- 

 pothesis proposed by Wallace, the codiscoverer with Darwin of evo- 

 lution. He believes that the earth is the only inhabited world in the 

 ^universe, citing as proofs the almost central position of the sun in the 

 galaxy, and the peculiar balance of gravitational and other forces thus 

 arising, and from the particular 'position of our planet in the solar 

 system. There can be no doubt that the position of the earth is 

 unique, and must necessarily be, because of the principle that two 

 bodies cannot occupy the same space at the same time. It is also in- 

 capable of proof that any other member of the solar system is inhab- 

 ited, as it is equally impossible to prove the negative. The argument 

 of peculiar position and delicate balance of forces, however, seems 

 comparable to the reasons that a shark inhabiting the Caribbean sea 



