Life Conditions in other Worlds. 91 



called globigerince are found at depths varying from 50 to 3000 

 fathoms, and he obtained a live star-fish from 1860 fathoms. At 

 the depth of a mile, the sea pressure amounts to 2640 lbs., or 

 160 atmospheres, on the square inch. The quantity of free air 

 or oxygen at these great depths must be very small, and 

 respiration low. We may also remark that animalcules can 

 exist in water placed under an air pump, and consequently 

 deprived of a great portion of its air. 



i The question of tfc j range of temperature that terrestrial 

 creatures can sustain has been considered in one of our recent 

 papers, entitled, " Aids to Microscopic Enquiry •" but, as we 

 have seen, we cannot tell the quantity of heat at the disposal 

 of organisms in the different worlds. Perhaps more light may 

 be thrown upon our speculations if we reflect upon the 

 remarkable discoveries of Tyndall, on the heat absorbing power 

 of aromatic vapours, that of aniseed being 372 times as great 

 as that of common air. Thus the existence, even in moderate 

 proportion, in the atmosphere of any planet, of some heat- 

 absorbing body not found in our own, might very materially 

 affect the temperature to which creatures living on it would be 

 exposed. 



In speculating on the power of animals in other worlds, of 

 either producing heat in very cold climates, or resisting it in 

 very hot ones, we may consider the bad conducting pro- 

 perties of many substances we are acquainted with, and of the 

 cooling action exerted by the evaporation of bodies taking up 

 considerable quantities of heat. Our terrestrial plants gene- 

 rate some heat in their vital processes, but, for the most part, 

 too little to enable them to accommodate themselves to a very 

 low temperature. There are, however, cases of very con- 

 siderable heat being generated by plants in their flowering 

 season, and Dr. Carpenter cites an instance of an Arum cardi- 

 folium raising a thermometer to 121°, while the temperature of 

 the surrounding air was only 66°. The main source of the 

 heat generated by plants and animals arises from a slow com- 

 bustion or oxydation of some of the materials they contain, and 

 we fiud terrestrial creatures adapted to an atmosphere contain- 

 ing only about one-fifth of oxygen. It would be a variation of 

 degree, not of kind, if in other worlds a larger proportion of 

 a gas supporting combustion were supplied, or if organized 

 beings were adapted to burn certain materials at a greater rate. 



Mr. Huggins's spectroscope researches lead us to the belief 

 that the atmospheres of the coloured stars absorb a sufficient 

 portion of the complementary rays to give them their peculiar 

 tint. Thus Betelgeux, an orange star, and Aldebaran, a pale 

 red one, exhibit spectra full of lines in the places of rays com- 

 plementary to the star tint. Aldebaran is described as having 



