THE MICROSCOPE. 45 



meeting of the New York Academy of Sciences, Mr. Romeyn Hitch- 

 cock read a paper on the above subject on the " Bioplasm Doc- 

 trine." 



The speaker devoted most of his paper to objections to Heitz- 

 mann and Elsberg's claim of having discovered a reticulum or net- 

 work in red and white corpuscles and in the amoeba. He said that 

 if these microscopists had seen it, others ought to be able to see it 

 also. Few people, it is true, know how to use a microscope, but 

 most people can see the most minute objects under a high power 

 glass when it has been properly adjusted and focused, hence he 

 denied Heitzmann's assertion that because a trvo can't see a thine 

 is no proof that it don't exist. 



The. speaker had several elegant microscopes on the table fitted 

 with the best high power objectives, and under one of these he 

 placed an amoeba, under another a pus corpuscle, and under two 

 others red blood corpuscles, to demonstrate the fact that no reticu- 

 lum or network exists, because none can be seen. It has been 

 claimed that this reticulum contracts and expands, thus causing 

 motion, and that some such reticulation is necessary to account for 

 the motions of protoplasm, but it may be asked how this can of 

 itself contract and expand. It is an explanation which fails to 

 explain. The speaker next referred to the three sources of error in 

 microscopic work : First, error in illumination ; second, error in 

 the correction of objectives ; third, errors in focusing. To demon- 

 strate the reticulum on red blood corpuscles, it is necessary to touch 

 them with a dilute solution of bichromate of potassium, but this 

 causes them to become granular, and as this action continues, it 

 breaks up the corpuscles. Such an effect was visible in one of the 

 slides exhibited under the microscope. It is claimed that reticulum 

 can be seen in the white corpuscles without this treatment, but such 

 was not the case here. Minute granules can be seen in amoeba, tut 

 no reticulum. In microscopy errors of interpretation are easily 

 made ; dots may merge into each other and be taken for lines, and 

 such may have been the case in the amoeba. — Scientific American. 



