1870.] with Becent Experiments. 487 



examined." It is to be regretted that we are not informed how long 

 the fluid was allowed to stand exposed to the air, for although 

 in the case under consideration the only result of the exposure was 

 the appearance of many " bacteroid particles " (whatever that may 

 mean — for a bacterium itself is the minutest speck perceptible to the 

 eye with high microscopic powers), " and monads of different sizes 

 exhibiting the most active movements," yet I will show presently, 

 that when certain fresh infusions are exposed under favourable cir- 

 cumstances only for a few hours, they become filled with perfectly- 

 organized plant forms in different stages of growth. In addition 

 to those " bacteroid " particles and monads, Dr. Bastian also found 

 " irregular-shaped particles " which were active, and the conclusion 

 at which I am constrained to arrive, is that his enthusiasm in the 

 cause of heterogenesis has led him, there at least, to confound the 

 atomic motion of organic and inorganic particles with the move- 

 ments of similar objects, of which it is always necessary to trace the 

 growth and development before they can be safely pronounced to be 

 the germs of infusoria or of lowly plants. 



Let me, in passing, recommend those investigators who are 

 reviving the experiments of Pouchet, Pasteur, Schulze, Joly, Musset, 

 Wyman, and others, all of whom have failed to convince the scien- 

 tific world, that they should not only examine their infusions, as 

 heretofore, some days after they have been sealed up, but some 

 hours afterwards, and I have reason to believe that the comparison 

 will change their views as to the result of closing and preserving 

 those infusions. 



Again, some of Dr. Bastian's experiments are strikingly adverse 

 to the hypothesis that the types observed and described were created 

 de novo. In experiment No. 13, a solution of tartrate of ammonia 

 and phosphate of soda, which had been kept twenty days in vacuo, 

 was found to contain a fungus, &c, whilst another solution, which 

 had been prepared in the same manner and at the same time, was 

 opened on the thirty-fifth day, and " yielded no organisms of any 

 kind ; " but mark ! when a third solution of the identical sub- 

 stances was so treated as to give free access to the air, and was 

 examined on the thirty-eighth day, there was found what the 

 observer calls " a spirally-twisted organism." It seems to me that 

 it would hardly be possible to adduce more convincing evidence 

 against heterogenesis and in favour of the atmospheric germ theory 

 than is afforded by these results, and a very striking confirmation 

 of this view is to be found in a circumstance which has recently 

 been discovered in another quarter, affording evidence, all the 

 more valuable, because it was not intended to influence this con- 

 troversy. Mr. Wood, of Middlesbrough, in his efforts to preserve 

 tartaric acid solutions in a state fit for chemical experiments, 

 has found that whilst such a solution will, under ordinary circum- 



