THE microscope:. 187 



A STUDY OF BLOOD. 



In the Transactions of the American Medical Asso- 

 ciation for the year 1875 appeared a paper by Dr. Louis 

 Elsberg, of New York City, entitled, " Notice of the Bioplasson 

 Doctrine." It gave the results of some researches carried on in the 

 laboratory of Dr. Carl Heitzmann, formerly of Vienna, but now of 

 New York, and was concerned with the structure of the cell. 



According to these observations, every cell contained fine fibres 

 which branched and inosculated and formed a close net-work, which 

 filled every part of the cell. This net-work was supposed to exist 

 in all cells, its contractions and relaxations to constitute the amoe- 

 boid movements of cells ; in short, it was supposed to be the 

 living matter of the cell. Before this time Dr. Heitzmann himself 

 had described the same thing in a paper before the Vienna Academy 

 of Sciences, in the year 1873, entitled "■Ban des Protoplasms'' 



Very little notice was taken of the subject at first, at least in 

 this country. But of late several papers on the subject in Europe, 

 and especially its favorable notice in Klein's Atlas of Histology, have 

 given it more prominence. 



The subject is one which differs from ordinary histological sub- 

 jects, such as the structure of a gland, or the termination of a nerve, 

 which persons interested in some other department of biology can 

 afford to ignore. It is concerned with the very foundations of 

 physiology and histology. It is of as much interest to the botanist, 

 the diatomist, or the student of life in any form, as to the student 

 of human physiology and histology. If the doctrine prove true, 

 we shall have made a long step in advance in the understanding of 

 cell growth, and shall have to unlearn many things which, until now, 

 we had supposed settled. As I am occupying a position where I 

 am expected to have some knowledge of my own about such things, 

 I have looked into the matter for myself. 



In order to make sure of pursuing the right course I wrote to 

 Dr. Heitzmann, asking him his method of demonstrating the struc- 

 ture, and received the following reply:* 



NEW YORK, -June 30, 1S79. 

 Lester Curtis, M. D., 



Dear Doctor. — In reply to your favor, date June 27, '79, I have to say as 

 follows: The Lens for seeing the structure ol I^rotoplasm must be a first 

 class i-io Immers., such as I use of Vcrick's, Hartnack's, Grunow's and 

 Toles' manufacture. Just the reticular structure itself is the best test for a 

 lens, so far as my own experience goes. 



*1 publish a careful copy of lhi»and ihc following letter, by Dr. Heitzroann's perinisaioii.— L.C. 



