THE ORIGIN OF BACTERIA AND OTHER MICRO-ORGANISMS 23 



2. The Vitalistic Hypothesis. This has also been designated the 

 "vital spark" theory or hypothesis. According to this concept it was 

 assumed that some mystical energy or force, or unknown and unknowable 

 power, gave rise to life. It was supposed that the difference between a bit 

 of dead organic substance and a bit of living organic substance was that 

 the living substance had been activated by some mysterious stimulus, the 

 vital spark. It was even suggested that this vital spark might be elec- 

 trical in nature, and some misguided scientists, in an attempt to harmonize 

 biological science with this essentially eclesiastical hypothesis of life, 

 suggested that life was due to the action of electrical discharges upon 

 organic matter. No scientist today subscribes to the vitalistic concept of 

 life. 



3. The Panspermistic Theory. This is also known as the cosmozoic 

 theory and is one of the very latest attempts to explain the origin of 

 life upon our particular planet, namely the earth. Despite the boldness 

 and daring of the theory, it is well founded in the physical sciences and 

 it is well worth while to give it a more detailed consideration. 



According to the panspermia or cosmozoa theory there is an inter- 

 planetary distribution of germs. Only within comparatively recent times 

 has the idea become intelligently or rationally formulated. Flammarion 

 suggested that most of the planets were inhabited. De Montlivault 

 (1821) declared that the first terrestrial life came from the moon. Richter 

 (1865) impressed by the .writings of Flammarion, conceived the idea that 

 meteors might be the interplanetary carriers of seeds and perhaps of 

 plants and smaller animals. Ferdinand Cohn (1872) strongly supported 

 the idea of Richter which idea is beginning to receive serious attention 

 on the part of scientists generally. 



When a larger cosmic body collides with a planet, the impact causes 

 great disturbance and broken masses and particles are driven into space 

 in all directions. The heat generated by the impact would no doubt kill 

 all organisms in the immediate vicinity of the point of impact, even should 

 they survive the mechanical shock. However, there can be no doubt that 

 seeds and many of the lower forms of life could survive and these might 

 be transported to some neighboring planet. It is, however, not conceiv- 

 able how any of the more highly organized plants and animals could possibly 

 survive such a journey. Suppose a large mass, bearing upon it plants and 

 insects, should become detached from a planet and finally approach the 

 ' earth entering the layer of atmosphere, the heat generated by the friction 

 would certainly destroy all life present. 



The objections above set forth as to the meteoric origin of higher pan- 

 germs, such as higher animals, plants and seeds, does not apply to bacteria, 

 and other similar small organisms. Should a meteor or other planetary 



